OSP-6 1399 English Specification Draft [Document Type] Specification ['ritle of the In\rention] METIIOD OF PRODUCING ROUGHLY SHAPED MATERIAL FOR ROLLING BEARING [Teclu~icaFl ield of the Invention] [OOOI] The present invention relates to a method of producing a roughly shaped material for a rolling bearing. Priority is claimed on Japanese Patent Application No. 2013-23 1292, filed on November 7,201 3, the content of \vhich is incorporated herein by reference. [Related Art] [0002] For exatnple~ash own in FIG. 11( A), a roughly shaped material forformation of a bearing ring of a rolling bearing that is used in automobiles, industrial machinery, and the like is produced by a method including a process (hot forging) of heating steel composed of high-carbon clronle bearing steel to a forging temperature in a range of 1 100°C to 1200°C and perfornling plastic working with respect to the steel, a process of cooling a forged article that is obtained, and a process of performing an annealing treatment in u~hichth e forged article after cooling is heated to a soaking temperature in a range of 780°C to 810°C, and the forged article that is heated is slowly cooled down. In the method, after hot forging and cooling are performed to allow cementite to precipitate (refer to FIG. 1 l(B)), it is necessary to spheroidize cementite by performing an annealing treatment for 15 hours to 16 hours (refer to FIG. 11 (B)). Accordingly, the method has a disadvantage in that a long period of time is taken for production of the roughly shaped material. [0003] OSP-61399 English Specification Draft Accordingl~: so as to shorten the tinle required for production of the roughly shaped material, some of the present inventors have suggested a method of shorteni~lg or onlitting the spheroidizing a~inealitigb y heating steel composed of high-carbon clxome bearing steel to a temperature T in a range ofAel point to (Aem point+5O0C) \vl~ilec ontrolling a heating rate so that the heating rate in a tempe~aturera nge of 600°C or higher is set to 10 "C/s or greater, and forging the steel at a temperature in a range of (Arl poi1lt+150~C)to Arl point in 10 minutes after reaching the tetnperatore T (for exa~nplere fer to Patent Document 1). [Prior Art Document] [Patent Documcnt] [0004] [ ~ a G tD~otc utnetit 11 Japanese Unexamit~edP atent Application, First Publication No. 2009-242 18 [Disclosure of the Irnretltion] [Problems to be Solved by the Invention] [0005] According to the tnethod described in Patent Document 1, a spheroidal cementite structure, which is fortned tl~~ougsphli eroidizing annealing in the related art, can be formed by performing only forging without performing spheroidizing annealing. Accordingly, it is possible to shorten or omit the annealing treatment for a long period of time (15 hours to 16 hours). However, in the method described in Patent Document 1, in a case where steel co~nposedo f high-carbon chsotiie bearing steel is forged at a telnperature in a range of (Art point+l5O0C) to Art point, a desired spheroidal cementite structure is obtained, but grains of ferrite, \vhich is a matrix structure, are considerably refined depending on forging conditions or a portion of the OSP-61399 English Specification Draft roughly shaped matcrial that is obtained tllmngh forging. Along with the refi~lcment, hardness may rise to approximately Hw.350 to 11~400. I11 this case, machinability map decrease in accordance with the rising of the hardness, or additional processing may be difficult. [0006] The invention has been made in consideration of the above-described circumference, and an object thereof is to provide a method of producing a roughly shaped material for a rolling bearing, which is capable of producing the roughly shaped material capable of stably securing satisfactory machinabilit~: in a short period of time. [Means for Solving the Problenii] [0007] Accordi~igto an aspect of the invention, there is przided a method of producing a roughly shaped material for a rolling bearing by forging a steel composed of a high-carbon chrome bearing steel containing 0.7 mass% to 1.2 mass% of a carbon, and 0.8 mass% to 1.8 mass% of a chromium. The method includes (A) forging the steel to a predetermined shape \vliile heating the steel to a forging temperature in a range of (Ael point+25"C) to (Ael point+l05C), and cooling a forged article to a temperature of Ael point or lower, and (B) performing an annealing in which the forged article obtained in (A) is heated to a soaking temperature in a range of (Ael point+2S0C) to (Ael poillt+85"C), the forged article is retained for 0.5 hours or longel; and the forged article is cooled down to 700°C or lower at a coolitig rate of 0.30 "CIS or slower. [OOOS] According to the method of producing a roughly shaped material for a rolliilg bearing of the invention, it1 the process (A), the steel composed of high-carbon clu.oine OSP-6 1399 Englisli Specification Drafl bearing steel is forged (warn forged) at a forging temperatnre in a range of (Ael point+25"C) to (Ael point+l05"C), al~dis cooled down to a temperature of Ael point or loxvcr to form fine spheroidal cementite in a state of being dispersed in a structure of steel. Then, in tlie process (B), the forged article that is obtained is retained at a soaking temperature in a range of (Ael pointt25"C) to (Ael point+85OC) for 0.5 11ours or longer and is cooled down to 700°C or lower at a cooling rate of 0.30 "CIS or slower so as to grow the fine splleroidal cementite to a relatively large size. Accordingly, it is possible to fu12lier sliorteti the production time in comparison to a production method in the related art in which steel is subjected to plastic working (hot forging) by heating the steel to a forging temperature of 1100°C to 1200°C. Furtlierniore, it is possible to obtain a roughly shaped material capable of securing satisfactory machinability during production of bearitig rings and the like. In the method of the related art (method described in Patent Document l), steel composed of high-carbon chrome bearing steel is forged at a temperature it1 a range of (Arl point+l5O0C) to Arl point to form spheroidal cenientite. However, in the method of the related art, even when the steel is forged under desired conditions, a locally fine ferrite structnre is fornled due to heat extraction through contact with a die or air, and the like. Therefore, a variatio~is likely to occur in a distribution of hardness due toa fine structure, in a state of a microstmcture, and a distribution of the a~nouuot f residual austenite after a quenching and te~nperingtr eatment (hereinafter, also referred to as "QT" treatment) due to unevenness of the microstructure. However, according to tlie method of producing a roughly shaped material for a rolling bearing of tlie invention, after forging and cooling (the process A), the forged article that is obtained is annealed by retaining the forged article at a soaking temperature in a range of (Ael point+25'C) to (Ael point+85"C) for 0.5 honrs or longel; and by cooling OSP-61399 English Specification Draft the forged article to 700°C or lower at a cooling rate of 0.30 "CIS or slower. Accordingly, it is possible to effectively suppress occulrence of a variation in the distribution of hardness, the state of the microstructore, and the distribution of the amount of residual anstenite after the QT treatment. [0009] In the method of producing a ronglily sliaped material for a rolling bearing of the invention, it is preferable that the soaking tetnperatnre in the process (B) is set to 760°C to 820°C. In this case, it is possible to more efficiently grow the spheroidal cementite. In addition, iu the method of producing a mughly shaped material for a rolling bearing of the invention, it is preferable that the cooling rate in the process (B) is set to 0.30 "CIS or slo\ver. In this case, formation of sheet-shaped or layered cenlentite is suppressed. Accordingly, it is possible to more efficiently grow the spheroidal cementite. [Effects of the Invention] [OOlO] According to the method of producing a roughly shaped material for a rolling bearing of the invention, it is possible to produce a roughly shaped material capable of securing n~achinabilityin a sliol-t period of titne. [Brief Description of the Drav.~ings] [OOI 11 FIG. 1 is a cross-sectional view of a rolling bearing including bearing rings \vI~icha re foinled by a rouglily shaped material for bearing rings which is produced by a production method according to an e~nbodimetito f the invention. FIG. 2 is a process diagram showing a sequence and heat treatment conditions OSP-61399 English Specification Draft of the prodoction method according to the ctllbodi~llento f the invention. FIG. 3 is a process diagram showing a sequence of a warn1 forging process in the production method according to the enlbodin~enot f the invention. FIG. 4 is a drawing-substituting photograph showing results obtained by observing a st~~lctusrtea te in each process of the production method according to the embodinlent of the invention, (A) is a draxxring-substihlti~tillpg hotograph of a steel structure before the warm forging process, (B) is a drawing-substituting photograph of a structure of a forged article at the time of terminating the warm forging process, and (C) is a drawing-substituting photogaph of a structure of a roughly shaped material for bearing rings which is obtained after an annealing process. FIG. 5 is a view showing results obtained by investigating a relationship between a soaking temperature and hardness, and results obtained by observing a structure of a roughly shaped material for bearing rings which is obtained after an annealing process in Test Example 3. (a) is a graph showing the results obtained by investigating the relationship between the soakiug temperature and the hardness, (b) is a drawing-substituting photograph of the structure of the roughly shaped material for bearing rings when the soaking tetnperature is set to 740C, (c) is a drawingsubstituting photograph of tl~est ructure of the roughly shaped material for bearing rings when the soaking temperature is set to 760°C, (d) is a drax41ing-substituti~lg photograph of the strocture of the roughly shaped material for bearing rings ~vhenth e soaking temperature is set to 820°C, and (e) is a drawing-substituti~lgp hotograph of the structure of the roughly shaped material for bearing rings when the soaking temperature is set to 840°C. FIG. 6 is a view showitlg results obtained by investigating a relationship between a cooling rate and hardness, and results obtained by observing a structure of a OSP-61399 Englisli Specification Draft roughly sliaped material for bearing rings \vI~icIi s obtained after an annealing process in Test Example 5. (a) is a graph showing the results obtained by investigating the relationship between the cooling rate and the hardness, (b) is a drawing-substituting photograph of the sttxlcture of the ronglily shaped material for bearing rings when the cooling rate is set to 7 "Clnli~(i 0.12 'Cis), (c) is a drawing-substituting photograpli of the striicture of the roughly shaped material for bearing rings when the cooling rate is set to 16 oC/ini~(l0 .27 "Cls), (d) is a drawing-substituting photograph of the structure of the roughly sliaped material for bearing rings when the cooling rate is set to 26 "Clnlin (0.43 "Cis), and (e) is a drawing-substituting photograpli of the structure of the roughly shaped material for bearing rings when the cooling rate is set to 93 OCImin (I .55 'CIS). FIG. 7 is a view showing results obtained by investigating a relationship behveen a cooling temperature and hardness, atid results obtained by observing a structure of a roughly shaped material for bearing rings which is obtained after an annealing process it1 Test Example 6. (a) is a graph sho\ving the results obtained by investigating the relationship between the cooling temperature and the hardtiess, (b) is a drawing-substituting photograph of the structure of the roughly shaped material for bearing rings when the cooling temperature is set to 650°C, (c) is a drawingsubstituting photograpli of the structure of the rouglily shaped ~nateriafl or bearing rings when the cooling temperature is set to 700°C, and (d) is a drawing-substituting photograph of the structure of the roughly shaped material for bearing rings when the cooling temperature is set to 730°C. FIG. 8 is a diagram showing heat treatment conditio~isin Example 1. FIG. 9 is a diagram showing heat treatment cotiditions in Exatnple 2. FIG. 10 is a drawing-substituting photograph sho\ving results obtained by OSP-61399 English Specification Draft observing a stlx~ctureo f a forged article that is obtained after an annealing process in Test Example 7. (a) is a drawing-substituting photogxaph sho~vinga result obtained by observing a structure of a forged article in Exatnplc 1, and (b) is a drawingsubstituting photograph showing a result obtained by observing a structure of a forged article in Example 2. FIG. 11 is a view showing heat treatrticnt conditions in a ~iletl~oodf p roducing a roughly shaped material for bearing rings in the related art in which hot forging is performed, and results obtained by observing a state of a structure in each process. [Embodiments of the Lnvention] [0012] Hereinafter, a niethod (hereinafter, also simply referred to as "production method") of a roughly shaped material for a rolling bearing i f the invention will be described in detail with reference to the accot~~panyindgra wings. FIG. 1 is a cross-sectional view of a rolling bearing includi~lgb earing rings which are formed by a roughly shaped material for bearing rings wliich is produced by a production method according to an ernbodimet~ot f the invetition. Furthermore, in this embodiment, description will be given of a conical roller bearing as an example of the rolling bearing, but the invention is not limited to the example. In addition, in this embodiment, description will be given of a roughly shaped material for fornlation of bearing rings (an inner ring and an outer ring) of the rolling bearing as at1 example of the rougl~lys haped material. I-Iowever, the invention is not limited to the exatiiple, and is also applicable to a roughly shaped material for formation of a rollitig body (roller, ball). A rolling bearing 1 sliown in FIG. 1 includes at1 i~lneri ng 11, an outer ring 12, a plurality of rollers (rolling bodies) 13 \vhich are arranged between the inner and outer OSP-61399 English Specification Draft rings I I and 12, and a retainer 14 that retains the plttrality of rollers 13. The inner ring 11 and the outer ring 12 of the rolling bearing 1 are fornled from a roughly shaped material for bearing rings (a roughly shaped material for an inner ring and a roughly shaped nlaterial for an outer ring) which is produced by the productioa method of the invention. [00 131 FIG. 2 is a process diagram showing a sequence and heat treatment cot~ditions of the production tnethod according to the embodiment of the invention, FIG. 3 is a process diagram showvitlg a sequence of a warm forging process in the production tnethod according to the eelnbodinlent of the invention, and FIG. 4 is a drawingsubstituting substituting photograph sl~owingre sults obtained by observing a structure in each procession 6Oa that is formed at a lower side of the inner tubular portion 60 (refer to (b) in FIG. 3). Then, in the separation and punching process, the inner tubular portion 60 of the formed blank B2 is punched by using a punch (not shown), and the bottom portion 6Oa of the inner tubular pollion 60 is punched by using the punch, thereby separating a forged article 51 for an outer ring and a forged article 61 for an inner ring from each other, and separating the forged article 61 for an inner ring and the bottonl portion 6lb from each other*to+fortn a prepared hole 61a in the forged article 61 for an inner ring (refer to (c) in FIG. 3). [00 191 After termination of forging, a forged article that is obtained is cooled down to a temperature (cooling temperature) of Ael point or lower (refer to (a) in FIG. 2). As described above, when the forged a~ticlteh at is obtained is cooled down to the cooling temperature, it is possible to efficiently form fine spheroidal cementite. The OSP-61399 Englisli Specilicatiot~ Draft cooling temperature is Ael point or lowel; and is preferably 400°C or lowel; fro111 the viewpoint of col~~pletecloyt npleting trat~sformnatiouo f an austenite strncture after termination of forging so as to suppress for~~~atoifo an p earlite structure and forn~ation of a martensite structure or a bainite structure which is an overcooled structure. In addition, the cooling tenlperature is preferably room temperature (25°C) or higher from the viewpoints of reducing a load on cooling facilities, improving production efficiency, and reducing productio~c~os t. A cooling rate when steel is cooled down to the cooling temperature can be appropriately deter~ninedin accordance with a co~npositiono f steel, a forging shape, and the like. Fut-thern~orei,n this specificatiot~t,h e "cooling temperature" represents a cooling temperature at the central portion of steel. - [0020] Tllrough the warm forging process, it is possible to form a structure (refer to step (B) in FIG. 2, and FIG. 4(B)) in which fine spl~eroidacl ementite is dispersed afier the \arm forging process (step (B) in FIG. 2) from a structure (refer to FIG. 4(A)) that includes pearlite before the waml forging process (step (A) in FIG. 2). [0021] (Annealing Process) In the at~nealit~pgro cess, first, the forged article, wvhich is obtained in the war111 forging process, is heated until the temperature of the central portion of the forged article reaches a soaking temperature in a range of (Ael point+2S0C) to (Aer point+8S°C) (refer to (b) in FIG. 2). [0022] The soaking ten~peraturei s (Ael point+2S°C) or highel; and is preferably (Ael point+3S°C) or highel; fsom the viewvpoint of obtaining a roughly shaped material OSP-61399 English Specification Draft capable of stably securing satisfactory macliinability. In addition, the soaking temperature is (Ael point+8S0C) or lower, and is preferably (Ael point+7S0C) or lower, fiom the vie\vpoitit of suppressirig fornlation of sheet-shaped or layered cementite. Specifically, the soaking tetiperature is 760°C or higher, and is preferably 770°C or highel; from the viewpoint of obtaining a roughly shaped material capable of securing satisfactory machinability. The soaking temperature is 820°C or lowel; and is preferably 810°C or lower, from the viewpoint of suppressing formation of sheetshaped or layered cementite. Furthermore, in this specification, the "soaking temperature" represents a soaking temperature at the central portion of steel. A temperature rising rate ~vhenh eating steel to the soaking temperature can be appropriately determined in accordance with a co~npositiono f steel, a forging shape, and tlie like. [0023 J When a temperature at the central portion of the forged article reaches a soaking tetnperature in a range of (Ael point+25"C) to (Ae, point+85'C), tlie forged article is retained at the soaking temperature for 0.5 hours or longer (refer to (b) in FIG. 2). The time (soaking time) for retention at the soaking temperature is preferably 1 .O hour or longer from the viewpoint of obtaining a roughly shaped material capable of stably securing satisfactory macliinabilitj~. Fu~-thennoree, ven when the soaking time is lengthened to be longer than 10 hours, an additional improvement in characteristics of the roughly shaped material, which corresponds to a period of the soaking time, is not exhibited. Therefore, it is preferable that the soaking time is as shorter as possible from the viewpoiilt of sl~o~tenittihge production time. The tipper limit of the soaking time is typically 5.0 lio~urso r shorten OSP-61399 Etiglisli Specificatioti Draft [0024] After the forged article is retained at the soaking time for 0.5 hours or longer, the forged article is cooled do\vti to a cooling temperature of 700°C or lower at a cooling rate of 0.30 "Cls or slower (refer to (b) in FIG. 2). The cooling rate is preferably 0.007 "CIS or fastel; and is Inore preferably 0.020 "CIS or faster, from the viewpoint of improving productivity (shortening of prodnction time). I11 addition, the cooling rate is 0.30 "CIS or slowel; is preferably 0.27 "CIS or slower, and is more preferably 0.25 "CIS or slower, fio~nth e viewpoint of suppressing formnatiotl of sheet-shaped or layered cernetitite. The cooling temperature is 700°C or lowel; and is preferably 650°C or lower, from the viewpoint of suppressing fornlation of sheet-shaped or layered cementite. In addition, the cooling temperature is preferably ro& temperature (25OC) or higher fiotii the viewpoints of reducing a load on eoolit~gfa cilities, improving production efficiency, and of reducing the production cost. [0025] Through the annealing process, fine spheroidal cementite (refer to FIG. 4(B)) is allowed to eficiently grow in a structure after the warm forging process (step (B) in FIG. 2). Accordingly, it is possible to fonn a structure (refer to FIG. 4(C)) in which the spheroidal cementite is dispersed after the atnieali~igp rocess (step (C) in FIG. 2). In this manner, it is possible to obtain a roughly shaped material for bearing rings of a rollitig bearing. Exatnples [0026] Next, the effect of a rolling Inember and a method of matiufacturitlg the rolling member according to the en~bodimenot f the invention will be verified with OSP-61399 English Specification Draft reference to exatuples aud the like. [0027] (Experiment Example 1) Steel (Ael=735"C) composed of high-carbon chrome bearing steel A (composition: 0.98 mass% of carbon, 1.48 mass% of chomiurn, 0.25 mass% of silicon, 0.45 mass% of manganese, 0.012 mass% of phosphorous, 0.006 mass% of sulful; and a remainder including iron and utlavoidable impurities) was forged and annealed under conditions shown in Table 1, thereby obtaining test pieces (model number: 6208) of a roughly shaped material for bearing rings in Experiment Nos. 1 to 17. [0028] [Table 11 OSP-61399 Englisli Specification Draft [0029] (Test Esamnple 1) Vickers hardness at 55 sites aruong the test pieces of Experiment Nos. 1 to 17 was tneasured in accordance with JIS Z 2244, and an average value of the Vickers hardness measured at the 55 sites was obtained. In addition, 5 mass% of picral etchant was brought into cotitact wit11 the central portion of each of the test pieces of Experiment Nos. 1 to 17 for 10 seconds to corrode the central portion, and then a corroded surface was obsenled with a scanning electron niicroscope (product name: EPMA-1600, manufactured by Shimadzu Corporation). Next, an evaluation of hardness arid structure spheroidizing, and an overall evaluatioti were performed for the respective test pieces. The results thereof are shown in Table 2. Fut-therrnore, the evaluation standards for the hardness and the structure spheroidizing, and for the overall evaluation of each of the respective test pieces are as follows. [0030] (Evaluation Standards for Hardness) Good: Vickers hardness is Hv240 or less. Poor: Vickers hardness is greater that1 Hv240. [003 11 (Evaluation Standards for Structure Spheroidizing) Good: Sheet-shaped or layered cementite is not sho~vna,n d spheroidal cemelltite is unifornlly dispersed in a stt-ucture. Poor: Sheet-shaped or layered cementite is sl~oun. [0032] (Evaluation Standards for Overall Evaluation) Good: Evaluation of the hardness and tlie evaloation of the structure OSP-61399 English Specification Draft spheroidizing are good. Poor: At least one of the evaluation of the hardness and of tic evaluation of the structure spheroidizing is poor. [0033] [Table 21 [0034] Fro111 results shown in Table 2, in a case where the follo\ving conditions were satisfied (Experiment Nos. 1 to 3,6, 10, 11, and 13 to IS), that is, in a case where the forging temperature was in a range of (Ael point+2S°C) to (Ael point+lOS°C), the cooling temperature after forging was Ael point or lowel; the soaking temperature during annealing was in a range of (Ael point+2S°C) to (Ae, point+8S°C), the soaking time \vas 0.5 horns or longer, the cooling rate after soaking was 0.30 'CIS or sl%ver, and the cooling temperatore \<'as 700°C or lower, it co~~bled s een that all of the test pieces which were obtained had Vickers hardness of I-Iv240 or less (hardness capable of stably obtaining satisfactory machinability), and had a structure in which sheet-shaped or layered cementite was not shown and spheroidal cementite was oniformly dispersed, and thus hardness and structure spheroidizing were suitable for the roughly shaped material for bearing rings. In contrast, in a case where the above-described conditions were not satisfied, that is, in a ease wvhere the soaking temperature was Ae, point+S0C (Experiment No. 12), Ael point+l05"C (Experiment No. 16), or Ael poitt+l35"C (Experiment No. 17), the soaking time was 0 hour (Experiment NO.'^), the cooling temperature after soaking was 730°C (Experiment No. 4) or 780°C (Experiment No. 5), the cooling rate after soaking was 0.50 "CIS (Experiment No. 7), and the cooling rate after soaking was 1.50 'CIS (Experiment No. 8), it could be seen that at least one of hardness and st~~~ctsuphrer oidizing of the test pieces was not suitable for the roughly OSP-61399 English Specification Drart shaped material for bearing rings. [0035] Even in a case using steel composed of high-carbon cl~ro~ibiea ring steel B (Ael=735'C) containing 1.0 mass% of carbon, 1.5 mass% of chromium, 0.3 inass% of silicon, 0.45 mass% of manganese, 0.01 mass% of phosphorous, 0.005 mass% of sulfur, and a re~nainderin cluding iron and unavoidable impurities, high-carbon clwome bearing steel C (Ael=735"C) containing 0.8 mass% of carbon, 1.4 mass% of chromium, 0.2 mass% of silicon, 0.4 mass% of manganese, 0.005 mass% of phosphorous, 0.004 mass% of sulful; and a remainder iticluding iron and unavoidable impurities, or highcarbon chrome baring steel D (Ael=745OC) coritainitlg 0.9 mass% of carbon, 1.7 mass% of chroniiom, 0.2 mass% of silicon, 0.45 mass% of tnanganese, 0.005 mass% of phosphorous, 0:005 inass% of sulfur, and a remainder including iron aid unavoidable impurities instead of steel cotnposed of the high-carbon chrome bearing steel A, it could be seen that the same tendency as in steel composed of high-carbon chrome bearing steel A was shown. [0036] (Experiment Example 2) Steel (Ael=73S°C) conlposed of high-carbon chrome bearing steel (coniposition: 0.98 mass% of carbon, 1.48 mass% of clwomium, 0.25 mass% of silicon, 0.45 mass% of manganese, 0.012 mass% of phosphorous, 0.006 mass% of solfin; and a remainder including iron and unavoidable impurities) was forged and annealed under conditions shown in Table 3, thereby obtaining test pieces (model number: 6208) of a roughly shaped material for bearing rings in Experiment Nos. 18 to 41. [0037] [Table 31 OSP-61399 English Specification Draft LO0381 (Test Example 2) The Vickers hardness at 55 sites atnotig the test pieces of Experiment Nos. 18 to 19 \?'as tneasured in accordance \\it11 JIS Z 2244, and the average value of the Vickers hardness nleasured at the 55 sites was obtained. In addition, 5 inass% of picral etcliant was brought into contact with the central portion of each of the test pieces of Experinlellt Nos. 18 and 19 for 10 seconds to corrode the ceutral portion, and then a corroded surface was observed with a scanning electron microscope (product name: EPMA- 1600, manufactured by Shimadzu Corporation). Furthermore, the test pieces of Experinlent Nos. 18 and 19 were produced ur~detrh e same conditions except that the tenlperature rising rates in the annealing process were different fiom each other. - [0039] As a result, it could be seen that all of the test pieces in Experiment Nos. I8 and 19 had a Vickers hardness of I-Iv240 or less (a hardness capable of obtaining satisfactor~mr achinability), and had a structure it1 which sheet-shaped or layered cementite was not shown and spheroidal cementite \+.as uniformly dispersed, and thus hardness and structure spheroidizing were suitable for the roughly shaped material for bearing rings (not shown). Accordingly, it is implied that an effect of the tenlperature rising rate in the annealing process on hardness and a structure state of the roughly shaped material for bearing rings is small. [0040] (Test Example 3) Vickers hardness at 55 sites anlong the test pieces of Experime~lNt os. 20 to 27 was measured in accordance with JIS Z 2244, and an average value of the Vickers l~ardr~etsnse asured at tl~e5 5 sites was obtained. In addition, 5 mass% of picral etchant OSP-61399 English Specification Draft was brought into contact with the central portion of each of the test pieces of Experiment Nos. 20 to 27 for 10 secollds to corrode the central portion, and then a corroded surface was observed with a scanning electron nlicroscope (product name: EPMA-1600, manufactured by Shimadzu Corporatio~i). Furtherniore, the test pieces of Experi~ncnNt os. 20 and 27 were produced under the same conditions except that soaking temperatures in the annealing process were different from each other. In Test Exanlple 3, results obtained by investigating a relationship between the soaking tenlperah~rea nd the hardness, and results obtained by observing the struch~reo f the roughly shaped ~llateriafl or bearing rings which was obtained after the annealing process are sl~ownin FIG. 5. In FIG. 5, (a) is a graph showing the results obtained by investigating the relationship between the soaking temperature and the hardness, (b) is a drawing-substituting photograph of the structure of the roughly shaped material for bearing rings when the soaking temperature is set to 740°C, (c) is a drawing-substih~ting photograph of the structure of the roughly shaped material for bearing rings hen the soaking temperature is set to 760°C, (d) is a drawing-substituting photograph of the structure of the roughly shaped material for bearing rings when the soaking temperature is set to 820°C, and (e) is a dralving-substituting photograph of the structure of the rouglily shaped material for bearing rings when the soaking temperature is set to 840°C. In the drawing, the scale bar represents 5 pm. [0041] As shown in FIG. 5, in a case where the soaking temperature is 760°C to 820°C ((Ael point+25OC) to (Ael point+85"C)) (Experiment Nos. 22 to 25), it could be seen that all of the test pieces which were obtained had a Vickers hardness of Hv240 or less (a hardness capable of obtaining satisfactory n~achinability)a, nd tended to have a structure in which sheet-shaped or layered cementite was not shown and spheroidal OSP-61399 English Specification Draft cementite \vas unifor~nlyd ispersed, and thos all of the hardness and structure spheroidizing were suitable for the roughly shaped nlaterial for bearing ritlgs. In contrast, in a case \vhere the soaking temperature was 740°C (Experimetlt No. 20), 750°C (Experiment No. 21), 840°C (Experiment No. 26), 850°C (Experiment No. 27), and 870°C (Experitilent No. 28), Vickers hardness of the test pieces was greater than Hv240 (the hard~~easts w hich machinability deteriorates), or the sheet-shaped or layered ce~nentitew as shown. Accordinglj: from the res~~ltist ,i s implied that the soaking temperature is preferably (Ael poi11t+25"C) to (Ael poil~t+XS~C). [0042] (Test Example 4) Vickers hardness at 55 sites among the test pieces of Experiment Nos. 29 to 33 was measured in accordance with JIS Z 2244, and an average value of the Vickers hardness measured at the 55 sites was obtained. In addition, 5 mass% of picral etchant was brought into contact with the central portion of each of the test pieces of Experiment Nos. 29 and 33 for 10 seconds to corrode the central portion, and then a corroded surface was observed \\it11 a scanning electron microscope (product natne: EPMA-1600, manufactured by Shimadzu Corporation). Furthermore, the test pieces of Experiment Nos. 29 to 33 were produced under the same conditions except that the soaking time in the annealing process is different fro111 each other. [0043] As a result, in a case where the soaking time was 0.5 hours (Experiment No. 30), 1 hour (Experiment No. 31), 1.5 hours (Experiment No. 32), and 2 hours (Experinlent No. 33), it could be seen that all of the test pieces which were obtained had a Vickers hardness of Wv240 or less (a hardness capable of obtaining satisfactory machinability), and had a struchlre in which sheet-shaped or layered cementite was not OSP-61399 English Specification Draft shown and spheroidal cementite was uniforn~lyd ispersed, and thus hardness and structure spl~eroidizing\I rere suitable for the ro~~ghslhya ped material for bearing rings (not showvn). In contrast, in a case where the soaking time was 0 hour (Experiment No. 29), Vickers hardness of the test piece was greater than Hv240 (hardness at which tnachinability deteriorates) (not showvn). Accordingly, from the results, it is implied that the soaking time is preferably 0.5 hours or longer. [0044] (Test Example 5) Vickers hardness at 55 sites atnong the test pieces of Experinlent Nos. 34 to 37 was rneasured in accordance wvith JIS Z 2244, and the average value of the Vickers hardness measured at the 55 sites was obtained. In addition, 5 mass% of picral etchant was brought into contact with the central portion of each of the test pieces of Experiment Nos. 34 to 37 for 10 seconds to corrode the central portiot~a, nd then a corroded surface was observed with a scanning electron microscope (product name: EPMA-1600, manufactured by Shiniadzu Corporation). Furthermore, the tcst pieces of Experiment Nos. 34 and 37 were produced under the same conditions except that the cooling rates in the annealing process were different from each other. In Test Exa~nple 5, results obtained by investigating a relationship between the cooling rate and the hardness, and results obtained by observing the structure of the roughly shaped material for bearing rings which was obtained after the annealing process are shown in FIG. 6. In the dra\ving, (a) is a graph showving the results obtained by investigating the relationship betwveen the cooling rate and the hardness, (b) is a drawing-substituting photograph of the structure of the roughly shaped material for bearing rings when the cooling rate is set to 7 "Cln~in(0 .12 'CIS), (c) is a drawing-substituting photograph of the structure of the roughly shaped material for bearing rings when the cooling rate is OSP-61399 Englisll Specification Draft set to 16 "Clmin (0.27 "CIS), (d) is a drawing-substitt~tingp hotograph of the structure of the roughly shaped material for bearing rings when the cooling rate is set to 26 "Clnlin (0.43 "CIS), and (e) is a dra\+ing-substituting pl~otograph of the structure of the roughly shaped material for bearing rings \vllen the cooling rate is set to 93 'Cl~nin (1.55 "CIS). In the drawing, the scale bar represents 5 pn1. [0045] From the results shown in FIG. 6, in a case where the cooling rate was 0.12 'CIS (Experiment No. 34) and 0.27 "CIS (Experiment No. 35), it could be seen that all of the test pieces which were obtained had Vickers hardness of Hv240 or less (hardness capable of stably obtaining satisfactory ~nachinability)a, nd had a structure in which sheet-shaped or layered cementite was not shown and spheroidal cementite was uniformly dispersed, and thus hardness and structure spheroidizing were suitable for the roughly shaped material for bearing rings. In contrast, in a case where the cooling rate was 1.55 "C/s (Experiment No. 37), it could be seen that the Vickers hardness of the test piece wvas greater than Hv240 (the hardness at which nlachinability deteriorates), and the sheet-shaped or layered cementite was seen. Accordingly, the results implies that ' the cooling sate in the annealing process is preferably 0.30 "C/s or lowel; and is more preferably 0.27 "CIS or lower. [0046] (Test Example 6) Vickers hardness at 55 sites among the test pieces of Experiment Nos. 38 to 43 was ~neasured in accordance with JIS Z 2244, and an average value of the Vickers hardness nleasored at the 55 sites wvas obtained. In addition, 5 mass% of picral etchant was brought into contact with the central portion of each of the test pieces of Experiment Nos. 38 to 43 for 10 seconds to corrode the central portion, and then a OSP-61399 English Specification Draft corroded surface was obset~fedw ith a scart~titige lectron ~tticroscope( product name: EPMA-1600, manufactured by Sliintadzn Corporation). Furthennore, the test pieces of Experinlent Nos. 38 and 43 were produced under the same conditions except that the cooling tentperaturc in the annealing process was different from each other. In Test Exantple 6, results obtained by investigating a relationship between the cooling temperature and the hardness, and results obtained by observing tlie structure of the roughly shaped material for bearing rings which is obtained after the annealing process are showvn in FIG. 7. In the drawing, (a) is a graph showing the results obtained by investigating the relationship between the cooling temperature and the hardness, (b) is a drawing-substituting pltotograplt of the structure of the roughly shaped material for bearing rings when the cooling temperature is set to 650°C, (c) is a drawing-substituting photograph of the structure of the roughly shaped material for bearing rings when the cooling temperature is set to 700°C, and (d) is a drawing-substituting photograph of the structure of the roughly shaped material for bearing rings when the cooling temperature is set to 730°C. In the drawing, a scale bar represents 5 pm. [0047] From the results shown in FIG. 7, in a case where the cooling temperature \%as 600°C (Experiment No. 38), 650°C (Experitnent No. 39), and 700°C (Experiment No. 40), it could be seen that all of the test pieces which were obtained had Vickers hardness of Hv240 or less (Itardness capable of obtaining satisfactory machinability), and tended to have a s t ~ ~ ~ c tinu rweh ich sheet-shaped or layered cementite was not showv~ai nd spheroidal cementite was uniformly dispersed, and thus tlie hardness and the structure spheroidizing were suitable for the roughly shaped material for bearing rings. In contrast, in a case where the cooling temperature was 750°C (Experiment No. 42) and 780°C (Experiment No.'43), it could be seen that there is a tendency where the Vickers OSP-61399 English Specification Draft hardness of the test pieces was greater than Hv240 (hardness at which machinability deteriorates), and tlie slie'et-shaped or layered cementite was shoowii. Accordingly, fio111 the results, it is i~iipliedth at the cooling temnperature in the atuiealing process is preferably 700°C or lower. [0048] (Exaniple I and Example 2) Steel (Ael=735"C) composed of high-carbon chronie bearing steel (composition: 0.98 mass% of carbon, 1.48 inass% of clwomiuti~0, .25 inass% of silicon, 0.45 mass% of manganese, 0.012 mass% of phosphorous, 0.006 mass% of sulfiil; and a remainder including iron and unavoidable impurities) was forged and annealed under conditions show~iin Table 4. Then, the forged articles which were obtained were subjected to a quenching treatment and a tempering treattilent urider conditions shown in FIG. 8 (Example 1) and under co~iditions hown in FIG. 9 (Exaniple 2), thereby obtaining test pieces (model tmmber: 6208) of a roughly shaped material for bearing rings. [0049] [Table 41 [0050] (Test Example 7) 5 mass% of picral etchant \wras brought into contact with the central portion of each of forged a~ticleasf ter the annealing process in Exa~ilple1 and Example 2 for 10 seco~~tdos c or~odetl ie central portion, and then a corroded surface wwras observed with a scamiing electron niicroscope (product name: EPMA-1600, nianufactured by Shimadzu Corporation). In addition, the \Tickers hardness at 55 sites among tlie test pieces of Exaniple 1 and Example 2 was measured in accordance with JIS Z 2244, and the OSP-61399 Et~glislS~p ecification Draft average value of the Vickers hardaess measured at the 55 sites was obtained. Ncxt, evaluation of hardtless of the respective test pieces and stl.acture spheroidizing of the forged articles after the annealing process was perforn~ed. In addition, the X-ray diffraction intensity was measured at a surface layer portion and the center portion of the test pieces of the roughly shapcd material for bearing rings ill Example 1 and Example 2 by at1 X-ray diffraction method. The X-ray diffractiotl intensity Iy of fcc that is a crystal structure of residual austenite, and the X-ray diffractio~in~t ensity Iu of bcc that is a crystal st~ucttureo f a te~nperedm artensite were obtained. From the X-ray difFractiot1 intensity ratio which was obtained, the amount of residual austenite at the surface layer portion and the center portioll of the test pieces of the rooghlp shaped material for bearing rings in Example 1 and 2 was obtained by using the followi~~g theoretical Expression (I): 1 Ny-1 +(RylRa)x(IulIy) (1) ( h E~x pression, Vy represents the amount of residual austenite, Ry and Ru represent coefticients depending on crystal orientatiotls that is measured, Iy and la represent X-ray diffraction intensities). In test Example 7, results, wvllich are obtained by obsel-ving a structure of the forged article obtained after the annealing process, are sho\vn in FIG. 10. In the drawing, (a) is a drawing-substituting pllotograph showing a result obtained by obsei~ringth e structure of the forged article in Example 1, and (b) is a drawingsubstituting photograp11 showiilg a result obtained by obsewing the structure of the forged article in Example 2. Furthennore, a scale bar in the drawing represents 10 pm. The amount of residual austei~itca t the surface layer portion and the center portion of the test pieces of the roi~ghlys haped material for beariug rings in Exatnple 1 and Example 2, and results obtained by perforlning evaluatio~ol f the hardness of the OSP-61399 Englisli Specification Draft respective tcst pieces and tlie structure splieroidizing of the forged articles afler the annealing process are sliowvn in Table 5. In addition, tlie evaluation standards for the evaluation of tlie hardness of the respective test pieces, and tlie structure spheroidizing of the forged articles obtailicd after the annealing process are the same as the evaluation standards used it1 Test Example 1. I11 addition, a case wvliere the amount of residual austenite \\.as an amount (15 vol% or less), which is suitable for compatibility between securement of rolling fatigue life and securement of dimensional stability in bearing rings of a rolling bearing is regarded as "Good". [0051] [Table 51 [0052] From results sliown in FIG. I0 and Table 5, in Example 1 and Example 2 which satisfies conditions in which the forging temperature is in a range of (Ael poi11t+25~C) to (Ael point+105"C), the coolit~gte mperature after forging was Ael point or lower, the soaking temperature during annealing was in a range of (Ael point+25OC) to (Ael point+85'C) and the soaking tenlperahre during annealing was in a range of preferably (Ael point+35C) to (Ael point+75"C), the soakirig time was 0.5 hours or longel; the cooling rate after soaking wvas 0.30 'CIS or slower, and the cooling temperature was 700°C or lower, it can be seen that all of the amount of residual austenite, tlie liardness, and the structure spheroidizing are in ranges wvhich are suitable for manufacturing of bearing rings. [Brief Description of the Reference Symbols] [0053] 1: CONICAL ROLLER BEARING (ROLLING BEARING) 11 : INNER RING (BEARING RING) OSP-61399 English Specification Draft 12: OUTER RING (BEARING RING) EXPERIMENT No. 1 2 3 4 5 Ael ("C) 735 6 7 8 9 10 735 735 735 735 735 735 735 735 ---7 35 WARM FORGING PROCESS ----- 830(Ae1+95) 830(Ae,+95) 830(Ae,+95) 830(Ae,+95) FORGING TEMPERATURE ("C) 830(Ae1 +95) ANNEAL1 NG PROCESS 830(Ae,+95) 830(Ae7+95) 830(Ae,+95) 830(Ae,+95) 830(Ae1+95) COOLING TEMPERATURE ("C) AIR COOLING TEMPERATURE RISING RATE ("C/s) 0.08 AIR COOLING AIR COOLING AIR COOLING AIR COOLING 0.1 0 0.10 0.1 0 0.1 0 0.10 0.1 0 0.10 1.5 1 .O 1 .O 1 .O 1 .O 11 735 830(Ae1+95) AIR COOLING 0.40 AIR COOLING AIR COOLING AIR COOLING AIR COOLING AIR COOLING 700 700 700 700 700 pp 700 700 12 - 13 14 15 SOAKING TEMPERATURE ("C) I 780(Ae1+45) 0.40 0.40 0.40 0.40 16 0.40 0.40 0.40 0.40 0.40 735 735 735 735 SOAKING TIME (h) 1 .O 780(Ae1 +45) 780(Ae1 +45) 780(Ae, 4-45) 735 780(Ae1 +45) 780(Ae, 4-45) 780(Ae1 4-45) 780(Ae, 4-45) 780(Ae1 +45) 17 735 830(Ae1 +95) 830(Ae1+95) 830(Ae,+95) ---- 830(Ae1+95) COOLING RATE ("C/s) 0.1 0 1 .O 1 .O 1 .O 1 .O 830(Ae,+95) COOLING TEMPERATURE ("C) 600 1 .O 1 .O 1 .O 0.0 0.5 830(Ae1+95) AIR COOLING AIR COOLING AIR COOLING AIR COOLING 0.1 0 ppp 0.10 0.1 0 0.1 0 AIR COOLING 600 700 730 780 0.25 0.50 1.50 0.1 0 0.1 0 ppp AIR COOLING 0.40 0.40 0.40 0.40 600 600 600 700 700 740(Ae1+5) 760(Ae, 4-25] 800(Ae1 +65) 820(Ae, +85) 0.40 1 .O 0.40 870(Ae1+1 35) 1 .O [table 2 1 I EVALUATION EXPER l hlENT No. 1 2 3 4 5 6 7 8 HARDNESS (Hv240 or less) - 9 10 11 12 13 14 15 16 17 GOOD GOOD GOOD GOOD POOR GOOD POOR POOR STRUCTURE SPHEROlDlZlNG POOR GOOD GOOD POOR GOOD GOOD GOOD GOOD POOR OVERALL GOOD GOOD GOOD POOR POOR GOOD POOR POOR GOOD GOOD GOOD POOR POOR GOOD POOR POOR GOOD GOOD GOOD GOOD GOOD GOOD GOOD POOR POOR - POOR GOOD GOOD POOR GOOD GOOD GOOD POOR POOR [table 3 1 OSP-61399 English Specification Draft [Document T>lpe] CLAIMS What is claimed is: 1. A method of producing a roughly shaped material for a rolling bearing by forging a steel composed of a high-carbon chrome bearing steel containing 0.7 mass% to 1.2 mass% of a carbon, and 0.8 mass% to 1.8 mass% of a chroniium, the method comprising: (A) forging the steel to a predetermined shape while heating the steel to a forging temperature in a range of (Ael point+25OC) to (Ael point+l05"C), and cooling a forged article to a temperature of Ael point or lower; and (B) performing an annealing in which the forged article obtained in (A) is heated to a soaking temperature in a range of (Ael point+25"C) to (Ae, point+85"C), the forged article is retained for 0.5 hours or longer, and the forged article is cooled down to 700°C or lo\ver at a cooling rate of 0.30 "CIS or slower. 2. The method of producing a roughly shaped material for a rolling bearing according to Claim 1, \\~liereitit he soaking temperature is set to 760°C to 820°C. 3. The method.oPproducing a roughly shaped material for a rolling bearing according to Claim 1 or 2, \vlierein the cooling rate is set to 0.27 "CIS or slo\vel: