TIG焊对低合金钢焊缝金属元素分布状态的影响

Elemental distribution in weld metal of low alloy steel during TIG welding

采用TIG焊,选取两种成分相近的焊丝,制备了两组低合金钢焊接接头.通过焊材的EDS成分分析、焊缝金属XRF元素分析以及元素分布状态图等手段,研究了焊材及母材的合金元素在焊缝金属中的存在状态和分布特征.结果表明,锰在ER307Si焊缝中较高,镍、铬在ER308LSi焊缝中较高,硅在两组焊缝金属中相差不大;铬、镍、锰、硅在ER307Si焊缝中的起弧处含量较高,在ER308LSi焊缝中的中间处含量较高;起弧处元素分布较均匀,熔合线附近分布较稀疏;焊缝中间位置Ni元素分布较疏,含量较低;收弧处各元素分布不均.

Tungsten inert gas( TIG) welding of low alloy steel was conducted with two wires with similar chemical composition. After analysis of microscopic composition of welding material by EDS,elemental content analysis by XRF and elemental distribution state image in weld metal,the distribution of alloying elements in weld metal were studied. The results show that the alloying elements smoothly melted into the weld metal,the Mn content in weld with ER307Si wire was higher,but the Ni,Cr content in weld with ER308LSi wire was higher. The Si content in two welds were similar. The Cr,Ni,Mn and Si contents were higher in arc striking spot with ER307Si wire,but higher in the middle area with ER308LSi wire. The Ni content was low in the central part of the weld. The elements were distributed unevenly in the weld crater.