高碳钢片对铝硅镀层热成形钢激光焊接接头组织性能的影响

Effect of high carbon steel foil on microstructure and mechanical properties of laser welded Al-Si coated press-hardened steel

摘要: 以45号碳钢薄片为夹层，利用CWX3000光纤激光器对1.5 mm厚的铝硅镀层热成形钢进行激光焊接试验，研究焊缝碳含量对焊接接头显微组织和力学性能的影响. 试验结果表明，碳钢薄片的加入使焊缝碳含量增加，奥氏体相区扩大，焊缝δ铁素体的体积分数由17.3%降低至4.5%，焊缝平均硬度由425 HV增加至557 HV，焊接接头的抗拉强度由980 MPa增加至1 280 MPa，杯突值由1.7 mm增加至3.2 mm，抗拉强度及成形性能均有所提升.

Abstract: In this article, laser welding experiment of 1.5 mm thick Al-Si coated hot formed steel was carried out with 45 steel foil as interlayer by CWX3000 fiber laser. The effect of the carbon content of fusion zone on the microstructure and mechanical properties of the welded joint was studied. The results showed that after adding foil, the carbon content of fusion zone increased, the austenite phase zone was expanded, the δ-ferrite fraction of fusion zone decreased from 17.3% to 4.5%, the average hardness of fusion zone increased from 425HV to 557HV, the tensile strength of welded joint increased from 980MPa to 1280MPa, and the cupping value increased from 1.7mm to 3.2mm. Tensile strength and formability are both improved.