S450EW高耐蚀性耐候钢的焊接工艺

摘要

通过斜Y铁研抗裂性试验、拉伸、冲击、弯曲、金相组织、疲劳和周期浸润腐蚀试验对S450EW新型高耐蚀性耐候钢焊接接头进行了研究.结果表明:采用TH650EW-Ⅱ焊丝对S450EW新型高耐蚀性耐候钢焊接时,可获得拉伸、冲击、弯曲及抗裂性能均良好的焊接接头；S450 EW钢材的金相组织为回火索氏体(贝氏体+铁素体),晶粒度7～8级,非金属夹杂物中硫化物0.5 ～1级,氧化铝0级；与传统耐候钢相比,接头的疲劳强度和耐腐蚀性能均有大幅度提升,为我国铁路货车的实际生产提供了理论依据.%Mechanical properties and microstructures of S450EW weathering steel MAG welded joints were studied through crack resistance,tensile,bending,impact and periodical immersed corrosion tests and micro-structure analysis. The results show that tensile, bending and impact properties of the joint are all good with TH650EW- II wire. Microstructure of the S450EW is tempered sorbite ( bainite and ferrite) , the level of grain fineness ranges from 7 to 8, the level of non- metal enclosed slag ranges from 0.5 to 1, and the level of Al2 O3 is 0. Comparing lo traditional weathering steel,the fatigue strength and corrosion resistance improve significantly.