双相不锈钢电阻对焊接头的性能研究

STUDY ON THE PROPERTIES OF BUTT RESISTANCE WELDS OF STAINLESS STEELS

对瑞典产五种双相不锈钢电阻对焊接头的抗点蚀性能和力学性能进行了试验.结果表明,双相不锈钢,尤其是超级双相不锈钢,具有优良的抗点蚀性能和力学性能.其中,含钼、氮较高的SAF2205双相钢电阻对焊接头的临界点蚀温度CPT与对应母材相比有一定程度的下降,下降范围在10 ℃以内,力学性能下降幅度也不大,表现出较好的焊接性能和焊后抗点蚀性能.超级双相钢SAF2507电阻对焊接头的CPT几乎与母材的相同,高达65~68℃,力学性能略有下降,且热影响区窄,晶粒长大倾向小,表现出极好的焊接性能和焊后抗点蚀性能.文章对电阻对焊接头性能变化的原因从化学成分和显微组织方面进行了分析.

Duplex stainless steels, especially super duplex stainless steels have very smart corrosion resistance and properties of strength. The pitting corrosion resistance of as welded duplex stainless steels SAF2205 decreased in CPT about 10℃ from that of their base metals. The properties of strength decreased in an acceptable extent, showing good weldability and post pitting corrosion resistance. For the weld of super duplex stainless steel SAF2507, the CPT was as high as that of its base metal, about 65～68℃．The decrease of its properties of strength was very small. The width of its HAZ is rather narrow and the tendency of grain growing was also small, showing remarkable pitting corrosion resistance and weldability. The reason for the change in their properties is studied with chemical composition and microstructure analysis.