THE REASON ANALYSIS OF LOWER PERCENTAGE ELONGATION AFTER FRACTURE OF Q235B HOT-ROLLING HEAVY PLATE

By means of microstructure examination,chemical composition analysis of the steel,the phenomenon of lower percentage elongation after fracture of Q235B hot-rolling heavy plate was analyzed. The results showed that the lower percentage elongation after fracture is caused by band-structure and inclusion. In order to increase the percentage elongation after fracture,the band-structure and inclusion in the steel must be strictly controled.