The reason for inner crack of Q235 square billet is analyzed. It is considered that chemical component, molten steel temperature of tundish and drawing speed are the main elements.

• 分析了宣钢炼钢厂Q235方坯产生内裂的原因,认为化学成分、中包钢水温度和拉速是导致Q235方坯产生内裂的主要因素。