低碳铝镇静钢热镀锌板抗时效性能优化研究

Optimizing Research of Hot-Dip Galvanized Low Carbon Aluminum Killed Steel Sheet Aging Resistance

为提高低碳铝镇静钢热镀锌板的抗时效性能，研究了碳含量和卷取温度对热镀锌板抗时效性能的影响，并从热轧板碳化物的分布角度分析了产生影响的原因。结果表明，当碳含量为0.03％～0.06％时，碳含量越高，热轧板碳化物数量越多，碳化物之间的距离越短，热镀锌板抗时效性能越差；对于碳含量约为0.03％的铝镇静钢，当卷取温度为620—710℃时，随着卷取温度的提高，热轧板碳化物尺寸增大，热镀锌板抗时效性能提高。当卷取温度提高到730℃时，铁素体晶粒尺寸急剧增大，碳化物析出难度增加，热镀锌板抗时效性能降低。适当降低碳含量和适当提高卷取温度可有效提高低碳铝镇静钢热镀锌板抗时效性能。

To improve aging resistance of hot-dip galvanized low carbon aluminum killed steel sheet, the effect of carbon content and coiling temperature on aging resistance was investigated. The cause of effect was explored by analyzing the effect of carbide distribution in hot rolled plates on solid solution carbon of galvanized sheet. The results showed that carbon content and coiling temperature have effect on aging resistance. When carbon content was within 0.03%︿0.06%, more carbon led to shorter distance between carbides in hot rolled plates, which resulted in better aging resistance for hot-dip galvanized sheet. When coiling temperature was within 620︿710 ℃, higher coiling temperature led to bigger carbides in hot rolled plates, which resulted in better aging resistance for hot-dip galvanized sheet with about 0.03% carbon. Grain size of ferrite was very big in hot rolled plates when coiling temperature was 730℃, which led to less precipitation of carbides during annealing and worse aging resistance for hot-dip galvanized sheet. Properly decreasing carbon content or properly increasing coiling temperature were effective to improve aging resistance of hot-dip galvanized low carbon aluminum killed steel sheet.