高强度贝氏体钢棒料热轧裂纹及断裂原因分析

Analysis on Reason for Crack and Fracture of Hot Rolled High Strength Bainite Alloy Steel Bar Stock

高强度贝氏体钢棒料在热轧、校直及下料过程产生裂纹及断裂,结合棒料的生产过程分析产生裂纹及断裂的原因。结果表明,热轧过程出现裂纹主要与热轧过程轧制温度偏低,方坯料冷却过快,变形不均匀,抗力过大引起。冷校直过程的裂纹及断裂与棒料热轧冷却后硬度偏高,没有进行高温回火,进行冷校直而产生,并提出防止高强度合金钢热轧及冷矫直过程出现裂纹的措施。

Cracks and fractures appear in the process of hot rolling, straightening and blanking of high strength bainite steel bars. The causes of cracks and fractures are analyzed in combination with the production process of bars.The results show that the main causes of cracks in hot rolling process are low rolling temperature, rapid cooling of billet, uneven deformation and excessive resistance. The cracks and fractures in the cold straightening process are caused by the high hardness of the bar after hot rolling and cooling without high temperature tempering and cold straightening. The measures to prevent crack of high strength alloy steel are put forward.