热处理工艺对510 MPa级船板用钢组织及性能的影响

Effect of heat treatment process on microstructure and properties of 510 MPa grade ship steel

分别采用870、900、930℃淬火及620、650、680℃回火,研究不同热处理制度对510 MPa级船板用钢原始奥氏体晶粒度、显微组织、强韧性的影响。结果表明:510 MPa级船用试验钢随870、900、930℃淬火温度的升高,晶粒度变为7.5、7、6.5级,强度、平均冲击吸收能量下降;不同温度淬火试验钢随620、650、680℃回火温度升高,强度下降,平均冲击吸收能量均呈现先升高后下降趋势;510 MPa级船用试验钢在900℃×1.5 h淬火+650℃×2 h回火时具有优良的强韧性配合。对于强度有更高要求的试验钢可以选择870℃×1.5 h淬火+620℃×2 h回火。

Effects of different heat treatment on the grain size,microstructure,strength and impact absorbed energy of 510 MPa steel were studied by quenching at 870,900,and 930℃ and tempering at 620,650 and 680℃,respectively.The results show that with the increase of quenching temperature of 870,900 and 930℃,the grain size of 510 MPa ship steel becomes 7.5,7 and 6.5 respectively,the strength and the average impact absorbed energy decrease.With the increase of the tempering temperature of 620,650 and 680℃,the strength of specimen decreases,and the average impact absorbed energy increases first and then decreases.The 510 MPa grade ship steel has excellent strength and average impact absorbed energy when it is quenched at 900℃ for 1.5 h and tempered at 650℃ for 2 h.Quenching at 870℃ for 1.5 h and tempering at 620℃ for 2 h can be selected for higher strength requirements.