PROCESS OF MAKING A HIGH STRENGTH COLD REDUCED STEEL SHEET HAVING HIGH BAKEHARDENABILITY AND AN EXCELLENT NON-AGING PROPERTY

摘要

1514270 Heat-treating steel strip NIPPON KOKAN KK 18 Nov 1975 [18 Nov 1974] 47563/75 Heading C7A Steel containing in percentage by wt. C 0À02-0À12 Mn 10(%S)-2 N 0À003-0À02 is conventionally hot and cold-rolled to strip and is then subjected to a continuous annealing process in which it is heated to a temperature in the range Ac 1 -900‹C, held for 5-180 seconds and then quenched to room temperature in a jet stream of water. As a result the product has a structure containing 3-40% martensite. It is then reheated to 150-450‹C, held for 5-300 seconds, cooled to room temperature and coiled.