X90管线钢板调质处理后的组织与性能

本文对16.3 mm厚 X90管线钢板在不同调质处理工艺下的组织性能进行了研究。结果表明：930 ℃淬火温度下，随着回火温度的升高，钢板屈服强度先增加后降低，抗拉强度逐渐降低，从而导致屈强比升高；回火温度为630 ℃时，落锤剪切面中脆性区增多，落锤性能最差。在870 ℃两相区淬火，钢板组织中奥氏体晶粒大幅度细化，再经530 ℃回火，细化的马氏体或者贝氏体组织中出现亚结构的回复软化，板条边界钝化和M/A组元分解的综合作用，使该调质工艺下X90管线钢板的综合性能最佳。

Research on microstructure and properties of quenched X90 pipeline steel plate

The microstructures and properties of X90 pipeline steel plates produced by different quenching and tempering processes were analyzed. The result showed that quenching temperature at 930 ℃, the yield strength was firstly increased and then declined as the tempering temperature increased, while tensile-strength was decreased gradually and reached the lowest at 630 ℃ .So, the ratio of yield strength/tensile strength was increased and the DWTT value became the worst. Quenching temperature at 870 ℃ of two phase zone and tempering at 530 ℃, X90 pipeline steel plate had the optimum comprehensive properties. This could be attributed to the fine grain austenite microstructure after quenching at 870 ℃, the combined effect of recovery and softening of the dislocation sub-structure, the blunting mechanism along strip boundaries and the precipitation strengthening from decomposition of massive M-A after tempering at 530 ℃.