酒钢CSP流程Q345qD低温冲击性能改善实践

Practice of Improving Low Temperature Impact Properties of Q345qD in JISCO CSP Process

通过显微组织、析出物形貌的分析研究,对酒钢CSP流程生产的Q345qD桥梁钢低温冲击性能影响因素进行分析。结果表明:晶粒粗大及MnS带状夹杂是导致低温冲击性能偏低的主要原因,通过添加微合金元素Nb、V,细化晶粒,提高Mn、S含量比,采用快速冷却,CSP生产的厚度规格为11.85mm的Q345qD,各项力学性能优异,-20°低温冲击性能达到246.33J。

Through the analysis of microstructure and precipitate morphology,the influencing factors of low temperature impact properties of Q345qD bridge steel produced by JISCO CSP process.The results show that coarse grains and MNS banded inclusions are the main reasons for the low temperature impact properties.By adding microalloyed elements Nb and V,refining grains,increasing the content ratio of Mn and S,adopting rapid cooling,Q345qD with a thickness of 11.85mm produced by CSP has excellent mechanical properties,and the low temperature impact properties at-20°can reach 246.33J.