低合金结构钢Q345B 420 mm特厚板的研发

阐述了南阳汉冶特钢通过合理的成分设计、模铸浇注、钢锭加热、3800轧机轧制及热处理，成功地在转炉-LF+VD精炼-模铸浇注-加热-轧制-正火热处理生产线开发出了420 mm特厚保性能、保探伤低合金结构钢Q345B钢板。热处理后钢板性能检测，屈服强度在305～350 MPa，抗拉强度在500～555 MPa，伸长率在23%～28%，20℃纵向冲击功在109～287J，性能指标均达到了250 mm厚Q345B标准要求。

Development of Q345B Low-Alloy Structural Steel of 420 mm in Thickness

The paper expounds how the 420 mm super thick plate of low alloy structural steel Q345B with mechanical properties and flaw detection guaranteed was developed in Nanyang Hanye Special Steel Co.,Ltd.by appropriate composition design,ingot casting,heating,3 800 mm mill rolling and heat treatment,on the production line of converter-ingot casting-rolling-normalizing.After heat treatment,the steel plate was inspected.The results showed that the yield strength was 305 to 350 MPa,the tensile strength 500 to 555 MPa,percentage elongation 23% to 28% and the longitudinal impact energy at 20 ℃was 109 to 287 J.The properties satisfied the demand of the specification for 250 mm thick Q345B steel.