中文摘要：

针对St12、St16深冲钢激光拼焊板的焊接温度场分布对焊缝形状影响较大的问题,在分析试验钢板温度相关性、熔化潜热、对流及辐射对激光焊接温度场影响规律的基础上,建立了焊缝形状预测模型。在模型节点选取时提出了首尾节点控制法,使焊接温度场模拟时的节点选取具有更高精度,所得预测焊缝形状与实际焊缝形状吻合度高。提出了一种基于偏最小二乘回归（PLS）的焊缝及其热影响区晶粒尺寸预测模型。焊缝及其热影响区晶粒尺寸的预测精度均达95%,充分表明该模型与工艺试验结果吻合良好,验证了该预测模型的合理性及适用性。

英文摘要：

The weld shapes of St12 and St16 deep-drawing steels were influenced by transient temperature distributions.Based on the influence of temperature dependence,latent heat of fusion,convection and radiation,the weld shapes prediction model was built.Additionally,the first and last nodes control method was used in heat loading in order to make sure all nodes could be selected.Experimental results showed that there were no significant differences between the predictive and actual weld shapes.Furthermore,multiple regression prediction models of grain size in weld and heat affected zone（HAZ） were put forward based on PLS.The prediction accuracy of grain size in weld and HAZ was above 95%.Therefore,the proposed models are reasonable and applicable to examine deep-drawing steel for demonstrative purposes.