C、Mn、Cr对中碳MnB钢228节距履带淬透性的影响

Effect of C,Mn,Cr on Hardenability of Medium Carbon MnB Steel 228 Pitch Crawler Belt

针对碳含量≥0.30%的40SiMn2、35MnTiB和30MnTiB制造的履带板淬火后易出现细小裂纹,不能满足履带板抗断裂性要求。而生产的23MnB钢(/%:0.20～0.27C、0.80～1.10Mn、≤0.20Cr、0.000 5～0.003 0B)的淬透性HRC J_(1.5)42.5～49.0,J_(13.0) 17.5～37.0达不到228节距HRC J_(1.5)44～55和J_(13.0)≥35的要求,通过150 kg中频感应炉试验和120 t BOF-LF-RH-CC-轧制的工艺试验得出,当钢的成分调整为(/%):0.24～0.30C、1.10～1.50Mn、0.20～0.50Cr、0.000 5～0.003 0B时,钢的淬透性HRC J_(1.5)=48.0～50.0,J_(13.0)=42.5～46.5可满足228节距履带板的淬透性和抗断裂性要求。

As the quenched crawler belt manufactured by steel 40SiMn2, 35MnTiB and 30MnTiB （ C≥030% ） easily occurs micro-cracks that doesn＇ t meet the requirement of anti-fracture behavior, while the hardenability HRC Ji.5 42. 5 - 49.0 and J13.0 17.5 -37.0 of produced steel 23MnB （/%： 0.20 -0.27C, 0.80- 1.10Mn,≤0.20Cr, 0.0005 0. 003 0B） can＇ t meet the requirement of hardenability HRC J1.5 44 -55 and J13.o/〉35 for 228 pitch crawler belt, by 150 kg medium induction furnace test and 120t BOF-LF-RH-CC-rolling pilot commercial production it is obtained that as adjusted composition of steel is （/%） 0. 24 - 0. 30C, 1.10 - 1.50Mn, O. 20 - 0. 50Cr, 0. 000 5 - 0. 003 0B, the steel hardenability HRC J1.5 =48.0 -50. 0, Jl30 = 42. 5 - 46. 5, it meets the requirements of hardenability and anti-fracture behavior for 228 pitch crawler belt.