Aiming at the deterioration of plasticity and toughness of 9Ni steel and its welded joints for natural gas tank at low temperature,the influence of quenching and tempering heat treatment(QT)and two-phase zone heat treatment(QLT)on the low-temperature properties of welded joints of 9Ni steel after manual arc welding was studied.The results show that the QT heat treat-ment optimization scheme is quenching temperature 800℃,tempering temperature 570℃,the effect of quenching temperature on the low temperature performance of 9Ni steel is mainly completed by crack propagation work,tempering temperature on the low temperature performance of 9Ni steel joint is completed by crack formation work;The optimization scheme of QLT is the quenching temperature of 800℃,the intermediate quenching temperature of 670℃ and the tempering temperature of 570℃.The quenching temperature has little effect on the low temperature performance of 9Ni steel.The effect of the intermediate quenching temperature on the low temperature performance of 9Ni steel welded joint is mainly completed by the crack propagation work,and the effect of tempering temperature on the low temperature performance of 9Ni steel joint is mainly completed by the crack propagation work.
关键词
9Ni钢/焊接接头/调质热处理/两相区热处理/低温性能
Key words
9Ni steel/welded joints/QT heat treatment/QLT heat treatment/low temperature performance
维普
万方数据