Reasons Analysis and Improvement on Lower Yield Strength of HSLA Heavy H-beams

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.