TECHNICAL FIELD

Present disclosure relates in general to a field of material science and metallurgy. Particularly, but not exclusively, the present disclosure relates to a method of producing steel sheet with magnetic properties. Further, embodiments of the disclosure, disclose the method for producing steel sheet that exhibits ferritic microstructure with coarse grains and minimal presence of second phase particles.

BACKGROUND OF THE DISCLOSURE

Steel is an alloy of iron, carbon, and other alloying element. Because of its high tensile strength and low cost, steel may be considered as a most viable choice for major components manufacturing in a wide variety of applications. Some of the applications of the steel may include buildings, ships, tools, automobiles, machines, bridges, manufacturing electrical components and numerous other applications.

Steels used for manufacturing electrical components (hereinafter referred to as “electrical steels”) are generally classified as iron silicon alloys which are used for laminations in motor cores and generator cores. The steel used for manufacturing electrical components require superior magnetic properties such as low core loss and high magnetic permeability. The required magnetic properties in electrical steels are completely dependent on steel cleanliness, chemistry, texture, and grain size of the steel. The magnetic properties also depend on operational parameters of cold rolling the steel to the finished product.

Generally, multiple alloying elements are added for manufacturing steel with magnetic properties. Further, silicon is considered as a crucial alloying element for manufacturing electrical steels with desired magnetic properties. Silicon is conventionally added in the range of 3-3.2 wt.% for manufacturing steel with desired magnetic properties. Silicon improves the magnetic properties of the steel however, the processing of the steel in a steel plant becomes difficult. The processing of steel across the entire steel manufacturing process including continuous casting, hot rolling, cold rolling and removal of scale by pickling becomes extremely difficult due to composition of silicon. Consequently, addition of silicon to steel is generally not practised across many steel plants due to which the production of high-grade steel for electrical components is severely limited. Apart from silicon, aluminium is also added for inducing the required magnetic properties in steel. However, manufacturing of steel with excessive aluminium content poses similar challenges as that of silicon and processing of the steel becomes difficult.

The present disclosure is directed to overcome one or more limitations stated above or any other limitation associated with the conventional arts.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of the prior art are overcome by a method and a product as claimed and additional advantages are provided through the method as described in the present disclosure.

Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non limiting embodiment of the disclosure, a method for manufacturing steel sheet with magnetic properties is disclosed. The method includes aspects of casting, steel ingots of a composition, comprising carbon (C) in range of 0.02-0.1 wt.%, silicon (Si) in range of 0.2-0.8 wt.%, manganese (Mn) in range of 0.1-0.8 wt.%, sulphur (S) in range of 0.001-0.1 wt.%, phosphorous (P) in range of 0.01 -0.08 wt.%, aluminum (Al) in range of 1-2 wt.%, nitrogen (N) in range of 0.001-0.01 wt.%, tin (Sn) less than 0.001 wt.%, antimony (Sb) less than 0.001 wt.%, balance being Iron (Fe) optionally along with incidental elements.. The casted steel ingot is heated for a pre-determined time at a temperature ranging from 1100 °C to 1300 °C. The steel ingots are subsequently hot rolled into strips of pre-determined sizes. Further, the strips are cold rolled into a sheet of pre-determined sizes. Lastly, the cold rolled sheet is annealed at a temperature ranging from 800 °C to 950 °C to obtain steel sheet with magnetic properties. The steel sheet includes magnetic properties comprising of ferritic microstructure with coarse grains and with minimal presence of second phase particles.

In an embodiment, the steel ingot is forged before hot rolling and after casting and the steel ingot is cooled to room temperature before hot rolling.

In an embodiment, the cooled steel ingot is forged into plates of thickness ranging from 15 mm to 25 mm.

In an embodiment, the pre-determined time for heating the steel ingots ranges from 50 minutes to 70 minutes.

In an embodiment, the pre-determined size of the strips that are formed by hot rolling, ranges from 4 mm to 6 mm.

In an embodiment, the hot rolled strips are pickled in an acid bath for removal of scales.

In an embodiment, the pre-determined size of the steel sheet cold rolled from the strips ranges from 0.4 mm to 0.8 mm.

In an embodiment, the core loss value of the steel sheet is 6.95 W/kg at 1.5 T of saturation induction. In an embodiment, the steel is heated for about 1 hour.

In one non limiting embodiment of the disclosure, a steel sheet with magnetic properties, is disclosed. The steel sheet includes a composition of carbon (C) in range of 0.02-0.1 wt.%, silicon (Si) in range of 0.2-0.8 wt.%, manganese (Mn) in range of 0.1-0.8 wt.%, sulphur (S) in range of 0.001-0.1 wt.%, phosphorous (P) in range of 0.01 -0.08 wt.%, aluminum (Al) in range of 1-2 wt.%, nitrogen (N) in range of 0.001-0.01 wt.%, tin (Sn) less than 0.001 wt.%, antimony (Sb) less than 0.001 wt.%, balance being Iron (Fe) optionally along with incidental elements. The steel sheet includes magnetic properties comprises of ferritic microstructure with coarse grains and with minimal presence of second phase particles.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

The novel features and characteristics of the disclosure are set forth in the appended description. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

Figure. 1 is a flowchart illustrating a method for manufacturing steel sheet for motor laminations with magnetic properties, according to an exemplary embodiment of the present disclosure.

Figure 2 shows microstructure of the steel sheet that is annealed at 800 °C, according to an exemplary embodiment of the present disclosure.

Figure 3 shows microstructure of the steel sheet that is annealed at 870 °C, according to an exemplary embodiment of the present disclosure.

Figure 4 illustrates the texture of the steel sheet that is annealed at 870 °C, according to an exemplary embodiment of the present disclosure.

Figure 5 is a typical hysteresis loop of the steel sheet at 1 Tesla, according to an exemplary embodiment of the present disclosure.

Figure 6 is a typical hysteresis loop of the steel sheet at 1.5 Tesla, according to an exemplary embodiment of the present disclosure.

Figure 7 is a prediction of the core loss expected at thinner gages of the steel, according to an exemplary embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the description of the disclosure. It should also be realized by those skilled in the art that such equivalent methods do not depart from the scope of the disclosure. The novel features which are believed to be characteristic of the disclosure, as to method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular form disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a method that comprises a list of acts does not include only those acts but may include other acts not expressly listed or inherent to such method. In other words, one or more acts in a method proceeded by “comprises… a” does not, without more constraints, preclude the existence of other acts or additional acts in the method.

The present disclosure is explained with the help of figures of a method of manufacturing steel sheet with magnetic properties. However, such exemplary embodiments should not be construed as limitations of the present disclosure since the method may be used on other types of steels where such need arises. A person skilled in the art may envisage various such embodiments without deviating from scope of the present disclosure.

Figure. 1 is an exemplary embodiment of the present disclosure illustrating a flowchart of a method for producing steel sheet with magnetic properties. The steel produced by the method of the present disclosure, includes a ferritic microstructure with coarse grains and with minimal presence of second phase particles. The method is now described with reference to the flowchart blocks and is as below. The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the scope of the subject. The method is particularly applicable to cold rolled steel, and it may also be extended to other type of steels as well.

The method of manufacturing the steel sheet according to the present disclosure consists of a casting step followed by hot rolling step, cold rolling step and annealing. The various processing steps are described in their respective order below:

At block 101, a steel ingot of desired alloy composition is formed by any of manufacturing process such as casting including but not limited to continuous casting process. In an embodiment, the alloy may be prepared in at least one of air-melting furnace, and vacuum furnace. The steel ingot may have composition of carbon (C) in range of 0.02-0.1 wt.%, silicon (Si) in range of 0.2-0.8 wt.%, manganese (Mn) in range of 0.1-0.8 wt.%, sulphur (S) in range of 0.001-0.1 wt.%, phosphorous (P) in range of 0.01 -0.08 wt.%, aluminum (Al) in range of 1-2 wt.%, nitrogen (N) in range of 0.001-0.01 wt.%, tin (Sn) less than 0.001 wt.%, antimony (Sb) less than 0.001 wt.%, and balance being Iron (Fe) optionally along with incidental elements.

Liquid steel with the above-mentioned composition and range of alloying elements is continuously casted into the steel ingot. The liquid steel of the specified composition is first continuously casted by any known method including but not limited to conventional continuous caster. The casted steel ingots are further cooled to room temperature before being processed further. The steel ingots may be subjected to laminar cooling on a run out table with water being supplied at a pre-determined cooling rate. The run-out table usually includes a plurality of rollers for traversing the steel ingots. The run-out table may be configured with a plurality of nozzles at a significant height from the rollers. The nozzles may generate or spray a thin curtain of water or any other coolant on the steel ingots traversing on the rollers. The coolant flow from the nozzles may be adjusted to control the cooling rate of the steel ingots and the steel ingots may be cooled on the run-out table to the room temperature. The casted steel ingots may be forged into plates of thickness ranging from 15 mm to 25 mm after cooling of the steel ingots to room temperature.

The method then includes the step of heating the steel ingot as shown in block 102. After casting the steel ingot with the specified composition, the ingots may be heated in a furnace to a temperature ranging from 1100 °C to 1300 °C for a predetermined time. Further, the predetermined time ranges from about 50 minutes to 70 minutes. The reheating temperature may be greater than 1300 °C however may not be desirable since, higher reheating temperatures may lead to grain coarsening of austenite and excessive scale loss, therefore being limited to the range of 1100 °C to 1300 °C.

The method then includes the steps of hot working the steel ingot by a hot working process [shown in block 103] after casting the steel ingot. In an embodiment, the hot working process may include but is not limited to hot rolling. Hot rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness and to make the thickness uniform at high temperatures and hot rolling is carried out above the recrystallization temperature of the steel. After the grains deform during processing, they recrystallize, which maintains an equiaxed microstructure and prevents the metal from work hardening. In an embodiment, the steel may be hot rolled using a hot mill strip. During hot rolling, hot charged steel ingot may be subjected to roughing mill. The roughing mill usually consists of one or two roughing stands in which the steel ingot may be hot rolled back and forth few times repeatedly to reach the thickness requirement. Roughing the milled steel sheet may be further subjected to finish rolling. During finish rolling, the sheet surface may be subjected to further thickness reduction, surface finishing and dynamic recrystallization. The steel ingot may be hot rolled into strips of a size ranging from 4 mm to 6 mm. The hot rolling may include the roughing step above the recrystallization temperature and a finishing step below the recrystallization temperature when rolling is done in a conventional hot strip mill.

The hot rolled strip is further subjected to a pickling process. The pickling process is performed for removing scales and other surface defects from the strip. Further, pickling refers to a treatment that is used to remove impurities such as rust and scale from the surface of the strip. During hot working processes, an oxide layer (referred to as “scale”, due to the scaly nature of its appearance) develops on the surface of the metal. Before subjecting the steel sheet or strip to cold rolling processes, the hot rolled steel sheet goes through a pickling line to remove the scales from the surface and make it easier to work. The oxide layer and the impurities on the surface of the strip is removed by dipping the strip into a pickle liquor. The pickle liquor may be hydrochloric or sulfuric acid.

Referring to block 104, the method further includes the step of cold rolling the hot rolled steel strips at a predetermined cold rolling strain into a sheet of pre-determined size. The cold rolling process is similar to the above-mentioned hot rolling process however, the steel strip is rolled at a substantially lesser temperature or at the room temperature in cold rolling process. Cold rolling involves forcing the steel strip through two rolls that have a gap in between each other. When the steel strip is cold rolled, it is plastically deformed as it is forced between the two rolls. The metal is compressed by the rolls and the plastic deformation occurs in the direction of the rolling. Cold working plastically deforms the steel sheet at a temperature below its recrystallization temperature. The steel strip may be cold rolled into sheets of size ranging from 0.4 mm to 0.8 mm in multiple small passes and a lubricant may be used during cold rolling for minimizing heat generated due to friction. The cold rolling refines the microstructure, and a fine scale of the microstructure is created.

With reference to the block 105, the cold rolled sheet is annealed at a temperature ranging from 800 °C to 950 °C to obtain the steel sheet with magnetic properties. In an embodiment, the annealing is carried out in an argon gas atmosphere. The cold rolled sheet may be heated at a pre-determined rate and may be cooled off for a predetermined time. Multiple such iterations of heating and cooling the steel sheet may be conducted and the annealing temperature may range from 800 °C to 950 °C.

Example:

Further embodiments of the present disclosure will now be described with examples of composition of the steel. Experiments have been carried out on the steel by using method of the present disclosure.

Two steel sheets may be used as samples for analysis. The steel sheets are manufactured in the above-described method and one of the steel sheets is annealed at a temperature of 800 °C whereas the other steel sheet is annealed at 870 °C. Further, small samples may be cut from the steel sheets and may be prepared further into metallographic specimen by mounting, grinding followed by coarse and fine polishing using standard techniques. The final polished specimens may be etched with standard 2 vol% nital solution. An optical microscope as well as a Field Emission Gun Scanning Electron Microscope (FEGSEM) may be used to study the microstructure of the steel sheet sample. Electron back scattered diffraction as well as x-ray diffraction tests may also be carried out to assess the crystallographic texture in the material. Further, the magnetic properties of the material were tested using a single strip test set up at a saturation induction of 1T and 1.5T.

Figure 2 shows micrographic view of the steel sheet that is annealed 800 °C and Figure 3 shows micrographic view of the steel sheet that is annealed at 870 °C. As seen in the microscope, the material revealed in the samples that were annealed at 800 °C and 870 °C which have a completely ferritic microstructure without any significant presence of second phase particles or inclusions. It is also observed that the microstructure of the steel grains was coarse when the samples were annealed at 800 °C and 870 °C. With reference to the Figure. 3, where the steel sheet sample was annealed at 870 °C, the microstructure included grains that were thicker and coarser when compared to the sample that was annealed at 800 °C. From the above samples, it is evident that grain coarsening occurs with increase in the annealing temperature. Figure 4 illustrates the texture of the steel sheet that is annealed 870 °C. X-ray diffraction technique was used for bulk crystallographic texture data of the sample that was annealed at 870 °C. The results as presented in Figure 4 indicated the consistency of the favourable texture components present in the steel sheet material.

It was observed that the samples annealed at 870 °C exhibited the required microstructure along with the favourable texture characteristics that are required for superior magnetic properties. Further, a single strip test set up was used to determine the B-H hysteresis loop where, B is the magnetic induction and H is the applied magnetic field. The test was conducted at a frequency of 50 Hz and the saturation induction was varied from 1 to 1.5 T. The subsequent hysteresis loop that was generated at 1T and 1.5 T are indicated in the Figures 5 and 6 respectively. The core loss value was found to be 4.67 W/kg and 6.95 W/kg respectively at 1 T and 1.5 T saturation induction. It is therefore observed that the favourable magnetic properties are induced in the steel sheet that is manufactured through above-disclosed method. The core loss data of the steel sheet manufactured from the above-disclosed method was found to be similar to the core loss data for semi-processed material of similar thickness but having a coarser grain size and without the presence of any favourable texture. Magnetic properties are sensitive to both grain size and the crystallographic texture of the steel sheet and the comparable core loss data of the material is due to the favourable texture components formed in the steel sheet that was annealed at 870 °C and is manufactured in the above-disclosed manner. It is therefore evident that, the excellent magnetic properties in the steel sheet are obtained mainly due to the favourable texture.

Figure 7 is a graphical representation of core loss in steel sheet at thinner gages. In an embodiment, the steel sheet annealed at the above disclosed temperature range of 800 °C to 950 °C and manufactured in the above-disclosed manner may be produced into thinner gage of the steel by any known method. With reference to the Figure 7, it is observed that the steel sheets that were further processed to thinner gage of steels exhibited lower core loss. It is also observed that the core loss is directly proportional to the thickness of the steel. The core loss was found to reduce proportionately with the reduction in the thickness of the steel. It was observed that the steel sheet that is processed to thinner gage steel with reduced thickness exhibited lower core loss.

In an embodiment, the method disclosed above with the annealing of the steel sheet in the temperature range of 800 °C to 950 °C induces ferritic microstructure with coarse grains in the steel sheet. The microstructure of the steel sheet also includes and minimal presence of second phase particles with favourable texture for superior magnetic properties. It was also observed that the steel sheet manufactured from the above-disclosed method was found to exhibit lower core loss. In an embodiment, the required magnetic properties in the steel sheet are solely induced by annealing the steel sheet in the temperature range of 800 °C to 950 °C and by manufacturing the steel sheet in the above-disclosed manner. In an embodiment, the usage of silicon is completely limited to the range of 0.2-0.8 wt.% of the steel and processing the steel becomes easier due to lower silicon content. In an embodiment, the manufacturing of the steel sheet with superior magnetic properties is not dependent on excessive usage of alloying elements such as silicon and is dependent on the annealing of the steel for inducing the required texture of the microstructure.

Equivalents:

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Referral Numerals

Referral Numerals Description
101 Casting a steel ingot
102 Heating the steel ingot
103 Hot rolling stage
104 Cooling stage
105 Annealing

Claims:

1. A method for manufacturing steel sheet with magnetic properties, the method comprising:
casting, steel ingots of a composition, comprising in weight%:
carbon (C) in range of 0.02-0.1 wt.%,
silicon (Si) in range of 0.2-0.8 wt.%,
manganese (Mn) in range of 0.1-0.8 wt.%,
sulphur (S) in range of 0.001-0.1 wt.%,
phosphorous (P) in range of 0.01 -0.08 wt.%,
aluminum (Al) in range of 1-2 wt.%,
nitrogen (N) in range of 0.001-0.01 wt.%,
tin (Sn) less than 0.001 wt.%,
antimony (Sb) less than 0.001 wt.%,
balance being Iron (Fe) optionally along with incidental elements;
heating the steel ingots for a pre-determined time at a temperature ranging from 1100 °C to 1300 °C;
hot rolling, the steel ingots into strips of pre-determined sizes;
cold rolling the strips into a sheet of pre-determined sizes;
annealing, the cold rolled sheet at a temperature ranging from 800 °C to 950 °C to obtain steel sheet with magnetic properties;
wherein, the steel sheet includes magnetic properties comprises of ferritic microstructure with coarse grains and with minimal presence of second phase particles.

2. The method as claimed in claim 1 wherein, the steel ingot is forged before hot rolling and after casting.
3. The method as claimed in claim 1 wherein, the steel ingot is cooled to room temperature before hot rolling.

4. The method as claimed in claim 3 wherein, the cooled steel ingot is forged into plates of thickness ranging from 15 mm to 25 mm.

5. The method as claimed in claim 1 wherein, the pre-determined time for heating the steel ingots ranges from 50 minutes to 70 minutes.

6. The method as claimed in claim 1 wherein, the pre-determined size of the strips that are formed by hot rolling, ranges from 4 mm to 6 mm.

7. The method as claimed in claim 1 wherein, the hot rolled strips are pickled in an acid bath for removal of scales.

8. The method as claimed in claim 1 wherein, the pre-determined size of the steel sheet cold rolled from the strips ranges from 0.4 mm to 0.8 mm.

9. The method as claimed in claim 1 wherein, core loss value of the steel sheet is 6.95 W/kg at 1.5 T of saturation induction.

10. The method as claimed in claim 1 wherein the steel is heated for about 1 hour.

11. A steel sheet with magnetic properties, comprising:
a composition in weight% of:
carbon (C) in range of 0.02-0.1 wt.%,
silicon (Si) in range of 0.2-0.8 wt.%,
manganese (Mn) in range of 0.1-0.8 wt.%,
sulphur (S) in range of 0.001-0.1 wt.%,
phosphorous (P) in range of 0.01 -0.08 wt.%,
aluminum (Al) in range of 1-2 wt.%,
nitrogen (N) in range of 0.001-0.01 wt.%,
tin (Sn) less than 0.001 wt.%,
antimony (Sb) less than 0.001 wt.%,
balance being Iron (Fe) optionally along with incidental elements;
wherein, the steel sheet includes magnetic properties comprises of ferritic microstructure with coarse grains and with minimal presence of second phase particles.

12. The steel sheet as claimed in claim 11 wherein, core loss value of the steel sheet is 6.95 W/kg at 1.5 T of saturation induction.