40MnB与16MnR异种钢的焊接性试验及工艺评定

40MnB是中碳合金结构钢,具有强度高、韧性好等性能,但其含碳量高,焊接性低,冷裂倾向大。16MnR属于低碳合金钢,具有良好的物理性能和工艺性能。两种钢在汽车上应用比较广泛。通过焊接接头无损检测、力学性能和组织金相分析,研究CO2气体保护焊40MnB和16MnR异种钢的焊接性能。结果表明,采用合适的焊接规范,所得的焊接接头各项性能良好,热影响区晶粒长大不严重,焊缝与母材熔合良好。

Weldability test and welding technology of dissimilar steel between 40MnB and 16MnR

The medium carbon steel 40MnB has advantage physical properties such as high strength and good toughness,but its high carbon content lead to bad weldability and high cold cracking tendency.The low alloy high strength steel 16MnR has good physical properties and weldability.The dissimilar welding joints between 40MnB and 16MnR are widely used in automobile industry.The dissimilar steel between 40MnB and 16MnR are welded by Carbon dioxide gas shielded arc welding.The microstructures and properties of welded joints are analyzed by means of optical microscope,mechanical properties and nondestructive testing.Results show that grain growth is not serious in Heat-Affected Zone and good fusion between weld and base material.Based on the present work,it is concluded that Carbon dioxide gas shielded arc welding is the suitable welding procedure for dissimilar metals between steel between steel 40MnB and 16MnR.