50Mn钢环形件的热处理

对外径1233 mm、内径1088 mm、高96 mm的50钢环形件进行了两种工艺的热处理:从碾压后的850~950℃直接水淬随后高温回火及锻造后调质处理。检测了热处理后环形件的显微组织和力学性能。结果表明:碾压成形后直接淬火随后回火的环形件的抗拉强度为859~874 MPa,屈服强度为528~564 MPa,断后伸长率为24%~26%,断面收缩率为64%~65%,冲击韧度为51~73 J;而锻造后调质处理的环形件的力学性能相应为抗拉强度850~865 MPa,屈服强度517~554 MPa,断后伸长率20%~22%,断面收缩率58%~60%,冲击韧度45~65 J,均符合要求,但总体上前者优于后者。经两种工艺热处理的环形件显微组织均未回火索氏体。碾压成形后直接淬火的工艺还具有节能降耗和缩短生产周期等优点。

Heat Treating of 50Mn Steel Ring

50Mn steel rings 1233 mm OD by 1088 mm ID by 96 high were heat treated as follows:(a) directly quenching in water from 850~950℃ after rolling followed by high tempering,and(b) quenching-and-tempering after common forging.After heat treating,the rings were tested for mechanical properties and microstructure.The results demonstrated that the ring quenched immediately after roller forming then tempered gave tensile strengths of859 to 874 MPa,yield strengths of 528 to 564 MPa,elongations of 24% to 26%,reduction in areas of 64% to65%,and impact toughnesses of 51 to 73 J,and the ring quenched and tempered after common forging gave mechanical properties which correspondingly were 850 to 865 MPa,517 to 554 MPa,20% to 22%,58% to 60%,and 45 to 65 J,which all conform the requirements,in general,however,the former is superior to the latter.The rings heat treated by the two procedures all exhibited tempered sorbite.The directly quenching after roller forming has the advantages of saving energy,reducing consumption and shortening production cycle.