X80级管线钢热加工敏感性研究

Heat Processing Sensitivity Research on X80 Grade Pipeline Steel

采用热模拟技术研究了不同化学成分的X80级管线钢对热加工的敏感性,以及不同加热温度对X80级管线钢的性能及金相组织的影响。试验结果表明,不同化学成分的X80级管线钢对热加工的敏感性不同。经过加热后,X80级管线钢的强度均有下降,特别是屈服强度值下降幅度较大;当加热温度为900-1 000℃时,屈服强度较低,但随着加热温度的升高,屈服强度和抗拉强度逐步增大;当加热温度达1 050℃以上时,强度值较高。随着加热温度的上升,材料金相组织的晶粒尺寸均呈增大的趋势,但增大幅度不同;当加热温度在1 000-1 050℃时,X80级管线钢的冲击韧性良好。综合组织特征的变化与材料的力学性能结果,当材料的淬火系数Di在1.1-1.3时,X80级管线钢对加热温度的敏感性较小;加热温度在1 000-1 050℃时,X80级管线钢的金相组织与力学性能较好。

Adopting heat simulation technology, the heat processing sensitivity of X80 grade pipeline steel with different chemical composition was researched, as well as effect of different heating temperature on performance and metallographic structure. Test results showed that X80 grade pipeline steel with different chemical composition had different sensitivity to heat processing. Through heating, strength of X80 grade pipeline steel decreased, particularly, yield strength value decreased greatly. When heating temperature was at 900 - 1 000 ℃, the yield strength was lower, but with temperature increasing, yield strength and tensile strength were growing up gradually ; when heating temperature was over 1 050 ℃, the strength was higher. With heating temperature increasing, grain size of material metallographic structure intended to the trend of becoming larger, but the extent of growing larger was different ; when heating temperature Was at 1000 - 1 050 ℃, the impact toughness of X80 grade pipeline steel was good. Organization characteristics variation and material mechanical performance showed that sensitivity to beating temperature of X80 grade pipeline steel was less, while quenching coefficient was 1.1 - 1.3 ; when heating temperature was at 1000 - 1050 ℃, the metallographic structure and mechanical property of X80 grade pipeline steel were better.