Q345T钢板桩力学性能不合格原因分析与探讨

通过采用化学分析、组织观察和力学检验等手段对Q345T钢板桩初检与复检力学性能检验结果差别较大的原因进行了分析。结果表明，组织中带状组织、魏氏体组织，以及带状的夹杂物是导致钢材强度低的主要原因。追溯钢材的整个生产过程可知，钢水冶炼时除杂除气不充分、板坯浇铸后期杂质聚集偏析、加热温度控制不均匀是造成钢材组织与性能不合格的根本原因。

Analysis and investigation on the reason for unqualified mechanical properties of Q345T steel sheet pile

Due to the great difference of mechanical properties between the preliminary and recheck tests of Q345T steel sheet pile, the reason was analyz by the means of chemical analysis, microstructure observation and mechanical performance test. The results show that the banded structure, Widmanstatten structure and banded inclusions are direct reasons for causing low tensile strength of steel. By tracing the whole production process of Q345T steel sheet pile, the inadequate removal of gas and inclusion, the aggregate segregation of impurities at late stage of slab casting, and the uneven heating temperature control are the root causes of unqualified microstructure and performances of the steel.