SAF2507双相不锈钢与 Q235碳钢异种金属板材的焊接

Research on welding of SAF2507 duplex stainless steel and Q235 carbon steel

将切割的Q235钢板和SAF2507双相不锈钢板分为4组,采用ZX7-400IGBT逆变式直流弧焊机和A302奥氏体不锈钢焊条进行焊接,并对焊前和焊后板材做微观组织分析及显微硬度分析。研究表明,在焊接电流为90A^130A的条件下,焊接熔合线附近的Q235钢一侧形成了脱碳层,SAF2507双相不锈钢一侧则形成了增碳层;随着焊接电流的增大,热输入也随之增大,焊缝长度变短,焊缝的余高增大,在熔合区的界面处发生碳迁移现象,使接头区域形成显著的硬度梯度。

Q235 carbon steel sheet and SAF2507 duplex stainless steel sheet were divided into four groups and welded by ZX 7-400IGBT inverter DC arc welding machine and A302 welding rod .The analysis of microstructure and hardness before and after welded was conducted .The results show that ：with the welding current of 90 A ~130 A ,the decarburization layer was formed near the welding fusion line on the side of Q235 carbon steel ,and on the side of SAF2507 duplex stainless steel ,the carbon layer’s thickness increased ;With the larger welding current ,the input welding heat increased ,the length of welding line increased ,the welding line’s height increased ,and the carbon migrant occurred at the interface of fusion zone ,which results in a significant hard-ness gradient on the joint zone .