摘要
本文研究了高强韧低合金冷模具钢6CrNiMnSiMoV(GD 钢)马氏体/下贝氏体复相热处理的组织和强韧性,以及下贝氏体和残余奥氏体量对 GD 钢强韧性的影响。结果表明,GD 钢复相热处理的强韧性明显优于常规热处理的强韧性,其工艺为900℃奥氏体化,250℃等温55min,空冷,180℃×2h 回火,此时组织中含有约27%的下贝氏体,具有最佳的强韧性配合,并进行了生产验证。
The microstructure and strength-toughness of a cold die steel6CrNiMnSiMoV(GD steel),which was undergone dual phase heat treatmentof martensite-lower bainite,have been investigated.The effects of theamount of lower bainite and retained austenite on the strength-toughness ofGD steel have been also studied.The results show that the strength andtoughness of GD steel treated by dual phase heat treatment are obviouslyhigher than that of GD steel treated by conventional method.The optimumcombination strength and toughness of the steel could be obtained as thevolume fraction of lower bainite is about 27 percent in low temperaturetempered state.The steel was austenitized at 900℃ and isothermally heatedat 250℃ for 55 min,air cooled,then tempered at 180℃ for 2h and this processis the optimum dual heat treatment and it is proved in production.
关键词
模具钢
复相热处理
强韧性
cold die steel
martensite-lower bainite dual phase heat treatment
strength and toughness
