This study concerns the weldability of dissimilar Ultra high-strength steel (UHSS) and advanced high-strength steel (AHSS), which is used in the modern machine industry. The materials offered superior strength as well as relatively low weight, which reduces microstructure contamination during a live cycle. The choice of the welding process base of the base material (BM) and welding parameters is essential to improve the weld joint quality. S700MC/S960QC was welded using a gas metal arc welding (GMAW) process and overmatched filler wire, which was performed using three heat input (7, 10, and 15 kJ/cm). The weld samples were characterized by a Vickers-hardness test, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The test reveals a decrease of softening areas in the HAZ and the formation of the stable formation of Bainite-Ferrite for S700MC and Bainite-martensite for S960QC when the heat input of 10 kJ/cm is used. It is recommended to use the GMAW process and Laser welding (Laser beam-MIG), with an optimal welding parameter, which will be achieved a high quality of manufacturing products.

中文翻译：

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焊接异种高强度和超高强度钢的可行性研究

这项研究涉及现代机械工业中使用的不同超高强度钢（UHSS）和高级高强度钢（AHSS）的可焊接性。该材料具有卓越的强度以及相对较低的重量，从而减少了在生命周期中的微观结构污染。选择母材（BM）的焊接工艺基础和焊接参数对于提高焊接接头质量至关重要。S700MC / S960QC使用气体保护金属电弧焊（GMAW）工艺和过度匹配的填充焊丝焊接而成，填充焊丝使用三个热量输入（7、10和15 kJ / cm）进行焊接。焊缝样品通过维氏硬度测试，扫描电子显微镜（SEM）和能量色散X射线光谱（EDS）进行表征。该试验表明，当使用10 kJ / cm的热量输入时，S700MC的热影响区软化区域减少，贝氏体-铁素体稳定形成，S960QC的贝氏体-马氏体稳定形成。建议使用GMAW工艺和激光焊接（激光束MIG），并选择最佳焊接参数，以实现高质量的制造产品。