许多石油机械的配件都是用40钢制造的。目前由于我国镍铬资源的不足,40钢供应困难,所以试制一种新的钢种——中碳锰钼钢来代替。根据我们使用的经验,这种钢(成分是碳0.40％,锰1.40％,钼0.15％)产生白点的可能性并不比铬钢小,在1200℃锻打后放在空气里冷却,往往发现有Ⅰ级白 Many petroleum machinery parts are made of 40 steel. At present, due to the lack of nickel-chromium resources in our country, 40 steel supply difficulties, so try a new type of steel - carbon-manganese steel instead. Based on our experience, this steel (composition 0.40% carbon, 1.40% manganese, 0.15% molybdenum) is not as likely to produce white spots as chrome steel, cooled at 1200 ° C in the air and often found I grade white