残余元素Sb对X80管线钢力学性能的影响

采用真空感应炉熔炼了不同Sb含量的X80管线钢，探究了Sb在钢中的存在形式及对其显微组织的影响，并通过维氏硬度测试、-20℃夏比冲击试验以及室温拉伸试验，研究了Sb含量对X80管线钢力学性能的影响。结果表明，X80管线钢中的残余元素Sb均匀分布在钢基体中；随着试样中Sb含量从0.0006%增加至0.0980%,钢中铁素体和珠光体的平均晶粒尺寸先增大后减小，钢的维氏硬度先增大后基本趋于不变，冲击吸收能量基本逐渐降低，而抗拉强度和屈服强度先降低再升高后略有降低，屈强比呈先减小后增大的趋势，伸长率略微下降。为保证X80管线钢的力学性能，应尽量减少钢中残余元素Sb含量。

Effect of residual element Sb on mechanical properties of X80 pipeline steel

X80 pipeline steel with different Sb contents was smelted in vacuum induction furnace, the effect of Sb on microstructure of the X80 pipeline steel and its existing form in the steel were investigated. The effect of Sb content on mechanical properties of pipeline steel was also studied by means of Vickers hardness testing, room temperature tensile testing and Charpy impact testing at -20 ℃. The results show that the residual element Sb in pipeline steel is uniformly distributed in the steel matrix. With the increase of Sb content from 0.0006% to 0.0980% in pipeline steel, the average size of ferrite and pearlite first increases and then decreases, the Vickers hardness firstly increases and then tends to be constant. The impact absorbed energy gradually decreases, basically, while the tensile strength and yield strength firstly decrease and then increase, and then slightly decrease. The yield ratio decreases firstly and then increases, and the elongation slightly decreases. In order to ensure mechanical properties of the X80 pipeline steel, the content of residual element Sb in the steel should be reduced as far as possible.