热冲压成形超高强钢焊接技术的进展

Progress in Welding Techniques for Hot Stamped Ultra-high Strength Steel

超高强钢在减小车身质量的同时能保证汽车的安全性。热冲压成形超高强钢尺寸精度高、使用寿命长,已被广泛应用于汽车制造领域。目前热冲压成形钢常用的焊接技术为电阻点焊和激光焊接等。为避免热冲压成形过程中表面氧化和脱碳,通常在钢板表面预制Al-Si镀层。然而镀层的存在会导致焊接接头力学性能降低。概述了可热冲压成形的超高强度钢及其镀层技术、热冲压成形钢常用的焊接技术以及焊缝组织和焊接接头的性能,探讨了改善热冲压成形超高强度钢焊接接头性能的途径。

Application of ultra-high strength steels(UHSSs)can reduce the weight of car body while ensuring the safety of the car.The hot stamped ultra-high strength steel possesses high dimensional accuracy and long service life,has been widely used in automobile manufacturing.At present,resistance spot welding and laser welding are commonly used for hot stamped steel.In order to avoid the oxidation and decarbonization of surface during hot stamping,Al-Si coating is usually prefabricated on the steel plate.However,mechanical properties of the welded joint will deteriorate in the presence of the coating.The ultra-high strength steels that can be hot stamped and the coating techniques for them,the welding technologies commonly used for hot stamped steel,as well as microstructure of the weld and properties of the welded joint were summarized.The approaches to improvement in properties of welded joint of the hot stamped ultra-high strength steels were discussed.