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An improved process for manufacturing wheels of railways wagons and coaches, having higher wear resistance, fracture toughness and strength, comprising the steps: (a) producing molten steel of composition, such as herein described, in an electric arc furnace of 10 tonne capacity by charging ingredients, such as herein described, in the furnace and additional ingredients, such as herein described, in ladles; (b) casting the molten steel into pencil ingots of weight 2 torne each in moulds, such as herein described; (c) cutting the ingots into blocks; (d) forging and rolling the blocks into wheels in a known manner; and (e) subjecting the wheels to a heat treatment, such as herein described; characterised in that (i) the ingredients charged into the furnace comprise wheel punch, ferro-alloys Fe-Si, Fe-Mn, Fe-Mo and aluminium bars, and the ingredients charged into ladle comprise ferro-alloy Fe-V and a slag containing lime-60%, Al shots - 25% and CaF2- 15% by weight, in proportion required to make the composition of the steel produced different from that of the existing composition by weight (C-0.52% max, Mn - 0.60/0.80% Si - 0.15/0.40%, Cr - 0.25% max, Ni - 0.25% max, Mo - 0.06% max, Cu - 0.28% max, V - 0.05% max, P - 0.03% max, S - 0.03% max and H - 3ppm) only in respect of the contents of micro alloying elements Mo, Al, V and Nb which are respectively, 0.20% max, 0.03% max, 0.20% max and 0.05% max by weight; (ii) the moulds used are pre-coated with graphite and pre-dried; and (iii) the heat treatment applied to the wheels comprises heating the wheels in a furnace to a temperature of 920-950°C, soaking thewheels at 920-950°C for one hour, and allowing the wheels to cool in natural air for 4-5 hours as against the existing heat treatment comprising heated and soaked quenching the rim of the similarly heated and sooked wheel for 5 minutes followed by tempering at 500° C temperature in furnace for 1.5 hours under hot charged condition and for 2.5 hours under cold charged condition and finally cooling in natural air.
Notices, Deadlines & Correspondence
Patent Information
Applicants
STEEL AUTHORITY OF INDIA LIMITED
Inventors
1. UMESH PRASAD SINGH
2. ANIL MOHAN POPLI
3. DINESH KUMAR JAIN
4. BASUDEO ROY
5. SUDHAKER JHA
Specification
Documents
Application Documents
| # | Name | Date |
|---|---|---|
| 1 | 524-cal-1998-granted-specification.pdf | 2011-10-06 |
| 2 | 524-cal-1998-granted-reply to examination report.pdf | 2011-10-06 |
| 3 | 524-cal-1998-granted-pa.pdf | 2011-10-06 |
| 4 | 524-cal-1998-granted-letter patent.pdf | 2011-10-06 |
| 5 | 524-cal-1998-granted-form 6.pdf | 2011-10-06 |
| 6 | 524-cal-1998-granted-form 3.pdf | 2011-10-06 |
| 7 | 524-cal-1998-granted-form 2.pdf | 2011-10-06 |
| 8 | 524-cal-1998-granted-form 1.pdf | 2011-10-06 |
| 9 | 524-cal-1998-granted-examination report.pdf | 2011-10-06 |
| 10 | 524-cal-1998-granted-drawings.pdf | 2011-10-06 |
| 11 | 524-cal-1998-granted-description (complete).pdf | 2011-10-06 |
| 12 | 524-cal-1998-granted-correspondence.pdf | 2011-10-06 |
| 13 | 524-cal-1998-granted-claims.pdf | 2011-10-06 |
| 14 | 524-cal-1998-granted-assignment.pdf | 2011-10-06 |
| 15 | 524-cal-1998-granted-abstract.pdf | 2011-10-06 |
| 16 | 00524-cal-1998 gpa.pdf | 2011-10-06 |
| 17 | 00524-cal-1998 form-5.pdf | 2011-10-06 |
| 18 | 00524-cal-1998 form-3.pdf | 2011-10-06 |
| 19 | 00524-cal-1998 form-2.pdf | 2011-10-06 |
| 20 | 00524-cal-1998 form-1.pdf | 2011-10-06 |
| 21 | 00524-cal-1998 drawings.pdf | 2011-10-06 |
| 22 | 00524-cal-1998 description(complete).pdf | 2011-10-06 |
| 23 | 00524-cal-1998 correspondence.pdf | 2011-10-06 |
| 24 | 00524-cal-1998 claims.pdf | 2011-10-06 |
| 25 | 00524-cal-1998 assignment.pdf | 2011-10-06 |
| 26 | 00524-cal-1998 abstract.pdf | 2011-10-06 |