Abstract: Surface crack on micro-alloyed steel plate produced by hot charging process was investigated by means of metallographic analysis, energy spectrometer analysis and contrast test of HCR and CCR. The results show that the main factors of surface crack on micro-alloyed steel plate produced by hot charging process are not the cracks on slab but the precipitation of a large of fine carbon and nitrogen compound at the boundary of the austenite grains,which decreases the strength of the grain boundary sharply.

摘要： 利用金相观察、能谱分析、连铸坯红送与冷送工艺的对比试验等手段，对红送工艺生产微合金钢板出现的表面裂纹进行了分析研究。结果表明,红送工艺生产微合金钢板表面裂纹并不是因为连铸坯本身存在裂纹缺陷，而是由于铸坯在凝固后的冷却过程中，大量细小的C、N化合物在奥氏体晶界析出，降低了晶界强度，导致钢板表面裂纹形成。

关键词: Nb-V-Ti微合金钢, 红送, 表面裂纹