回火时间对含铜HSLA钢板组织性能的影响

Effect of tempering time on microstructure and properties of HSLA steel plate containing copper

含铜HSLA钢板是高强度船舶用钢的理想材料,为确定其最佳热处理工艺,对不同回火时间下含铜HSLA钢板进行拉伸试验、冲击试验、测定宏观硬度,并借助OM、SEM等检测手段观察其金相组织。试验结果表明,随回火时间的延长,含铜HSLA钢板的基体组织中板条马氏体的板条结构逐渐消失,且钢板屈服强度、抗拉强度及硬度呈先升高后下降的趋势,室温冲击韧性提高,但低温冲击韧性变化不明显。回火时间为60 min时,钢板硬度、抗拉强度、屈服强度、伸长率各项性能达到最高值,分别为315.3HV、942 MPa、910 MPa、24%,为最佳热处理时间。

HSLA steel plate containing Cu is an ideal material for high strength marine steel.In order to determine the best heat treatment process, tensile test, impact test and macro-hardness measurement were carried out for HSLA steel plate containing Cu under different tempering time, and its microstructure was observed by OM and SEM.The results show that with the extension of tempering time, the lath structure of lath martensite in the matrix structure of HSLA steel plate containing Cu gradually disappears, and the yield strength, tensile strength and hardness of the plate first increase and then decrease.The impact toughness of plate at room temperature increases, but the impact toughness of plate at low temperature does not change significantly.When the tempering time is 60 min, the hardness, tensile strength, yield strength and elongation of the plate reach the highest value, which are 315.3 HV,942 MPa, 910 MPa and 24% respectively, which is the best heat treatment time.