Q345E厚板低温冲击性能不合原因分析与对策

针对首秦公司4300mm轧机生产60-85mm规格Q345E钢板低温冲击韧性不合问题，分析了其主要影响因素，指出钢板终轧温度高、粗轧道次压下量小，且轧后多采用空冷造成钢板带状组织严重，晶粒尺寸粗大是该问题的主要原因。在生产中通过增大粗轧道次压下率、降低精轧温度、采用水冷等措施，改善了Q345E厚板的低温冲击韧性，大大提高了产品的合格率。

Cause Analysis of Unqualified Low Temperature Toughness of Q345E Heavy Plate

In view of the unqualified low temperature toughness of 60-80mm Q345E heavy plate in Shouqin Co. , the main influence factors were analyzed. The high finishing rolling temperature, small reduction of roughing roiling and air cooling were pointed out to be the causes of unqualified, which result in the heavy banded structure and big grain size. Therefore, the countermeasures of increasing reduction of roughing, reducing finishing rolling temperature and applying water cooling were put forward, and the low temperature toughness of 60-80mm Q345E heavy plate can be greatly improved.