针对某批低合金高强度大规格H型钢屈服强度偏低的问题, 分析讨论了轧制工艺相同时, 钢的化学成分及显微组织对其屈服强度的影响。结果表明: 造成该批H型钢屈服强度偏低的主要原因是碳、硅、锰元素含量波动的影响, 显微组织对屈服强度的影响不大。据此提出了优化钢中化学成分、保证一定碳当量的改进措施。采取措施后产品的屈服强度平均提高了19~22 MPa, 取得了良好的效果。

Aiming at the problem of lower yield strength of HSLA heavy H-beams, the influences of chemical compositions and microstructure on the yield strength were analyzed and discussed under condition of the same rolling process. The results show that the fluctuation of carbon, silicon and manganese contents was the main reason for the lower yield strength, and the microstructure had little influence on the yield strength. So measures of optimizing chemical compositions and ensuring a certain carbon equivalent were proposed. After adopting these measures, average yield strength of the H-beams increased 19-22 MPa, and good results had been achieved.