摘要
为提高Q345C-Hq亚包晶桥板钢的热装温度,进行了入炉温度为600℃以上的热送直装试验,试验中发现多卷成品表面存在疤状缺陷。利用金相分析和电子探针分析得出,该缺陷是由铸坯冷却或加热过程中存在的裂纹经轧制后造成的;进一步用热模拟和计算的方法,求得该钢在不同温度状态下的表面应力和抗拉强度,得出有些情况下钢坯的表面拉应力已超出抗拉强度,从而使钢坯表面开裂。若钢坯出连铸机后堆冷,使钢坯内外温差减小到一定值后再进行加热,可有效避免裂纹的产生。
In order to increase the hot charging temperature of Q345C-Hq inferior wrap crystal bridge plate steel, the tests of over 600℃ charging temperature were carried out. But the scar defect on the surface of plate was found out. The causes were billet crack during cooling or heating analyzed by metallographic examination and electron probe microanalyzer. The heat simulation and caculation results show that the stretching stress of billet suface was over the strength limit to produce crack.Therefore, the resolution measure of eliminating the defect was cooling in packed formation of billet after casting which was reduced the temperature difference of inner and outer of billet.
出处
《轧钢》
2006年第4期10-13,共4页
Steel Rolling
关键词
热送热装
桥板钢
表面缺陷
温差
裂纹
hot delivery and hot charging
bridge plate steel
surface defect
temperature difference
crack
