TGK SPECIAL STEEL PVT. LTD. - HANDBOOK

The Name You Can Trust www.tgkssl.com - 57 - Descriptions and data in the file are typical cases. We will not make guarantee for them. Besides, we reserve the final right to interpret improvement in materials, quality and/or performance. Steel grade (S7 (SIHARD 2357 Steel) Description: S7 is a general purpose air hardening tool steel having high impact and sock resistance. it has good resistance to softening at moderately high temperatures. This combination of properties makes it suitable for many hot-work and cold-work applications. Applications : Chisels, rivet sets, punches, driver bolts. Hot punching and shearing. 3 Physical properties (average values) at ambient temperature : Density [gcm ] : 7.86 Equivalent Grades RAVNE OH253 MAT. NO. 1.2357 DIN 50CrMoV13-1 EN -- AISI/SAE S7 TG S7 Chemical Composition (in weight%) C 0.50 Si 0.50 Mn 3.25 Cr 3.25 Ni -- V 0.25 W -- Others -- Mo 1.50 -6 0 -1 Coefficient of Linear Thermal Expansion 10 C 0 20-100 C 11.7 12.9 13.3 14.1 14.3 14.6 13.8 0 20-200 C 0 20-300 C 0 20-400 C 0 20-500 C 0 20-600 C 0 20-700 C 0 Soft Annealing : Heat 810-850 C, cool slowly in furnace. This will produce a maximum brinell hardness of 229. Stress Relieving: To Relieve machining stresses for greater accuracy in hardening - first 0 rough machine, then anneal below the critical 649/677 C a minimum of one hour at temperature and cool slowly, then finish machine. 0 Hardening: Harden from a temperature 930-960 C followed by air or oil quenching. Hardness after quenching is 59-61 HRC. 0 Tempering : Tempering temperature: 150-400 C 0 Tempering Temperature( C) vs. Hardness (HRC) 0 100 C 59 57 54 52 48 41 53 0 200 C 0 300 C 0 400 C 0 500 C 0 600 C 0 650 C 52 0 550 C 0 Forging Hot forming temperature : 1060-1121 C Machinability : The machinability of S7 alloy may be rated at about 75/80 % of a 1% carbon tool steel. Corrosion Resistance : Corrosion resistance of this alloy is better than that of plain carbon steels. However it will rust unless given protective treatment. Forms manufactured : Please see Dimensional Sales Programe. COLD WORK STEEL