| 摘要 |
<p>An air hardening steel for bearings, tools and seamless tubes consists of the following:- .C.0.7-0.8% .Cr.0.9-1.2% .Mn.1.05-1.35% .Mo.1.2-1.4% .Ni.1.3-1.65% .Si.0.2-0.35% .Fe.the remainder The composition of the steel is such that when tested in sections up to 5 inch diameter which have been cooled from 1500 - 1650 DEG F and tempered at 300 - 400 DEG F, it has a hardness of 60 R.C. or above. Ingots of the steel should be equalized at 1300 - 1400 DEG F and forged at 2100 - 2200 DEG F. Suitable annealing treatments are: - (a) equalization at 1500 DEG F, furnace cooling to 1280 DEG F followed by cooling at 10 DEG F per hour to 1100 DEG F, then air cooling resulting in a spheroidized structure, or (b) equalization at 1650 DEG F, furnace cooling to 1280 - 1300 DEG F, cooling at 10 DEG F to 1100 DEG F and discharge resulting in a lamellar structure.</p> |
