控轧控冷工艺对X60管线钢组织及力学性能的影响

EFFECT OF THERMO-MECHANICAL CONTROL PROCESS ON MICROSTRUCTURES AND MECHANICAL PROPERTIES OF X60 PIPELINE STEEL

探讨了控轧控冷工艺参数对Ｘ６０管线钢组织和力学性能的影响．分析得出了控轧控冷工艺参数与力学性能关系的回归方程： бｓ＝０．５０７５ｔｓ－０．２３８７ｔｆ－０.３２４２ｔｃ＋１.１６３ｖｃ＋３２４．８２８７，δ＝－０．００１７ｔｓ－０．０５８５ｔｆ－０.０９７６ｔｃ＋０．３１６２ｖｃ＋１２３．９７，给出了一种较佳的工艺制度．微观结构分析表明，针状铁素体为主的混合组织，有较高的屈服强度和良好的韧性．

Effects of technological parameters of thermo-mechanical control process (TMCP) on microstructure and mechanical properties of X60 pipeline steel have been investigated. Regression equations describing the relationship between technological parameters and mechanical properties are obtained: sigma (s)=0.5075t(S)-0.2387t(f)-0.3242t(C)+ 1.9163 upsilon (C)+324.8287, delta (5)=-0.0017t(S)-0.0585t(f)-0.0976t(C)+ 0.3162 upsilon (C)+123.97, where t(S), t(f) and t(C) are the start rolling temperature, final rolling temperature and final colling temperature (degreesC), respectively, and vc cooling rate (degreesC /s). The parameters of TMCP for obtaining better mechanical properties are given. The experimental results show that the mixed microstructure mostly composed of acicular ferrite has the optimum strength and ductility.