论文部分内容阅读
本文就00Cr18Ni5Mo3Si2双相不锈钢焊接热影响区组织转变特征及其对性能的影响进行了探讨。采用焊接热模拟再现了热影响区的组织。采用焊接热循环加热—水淬法固定热影响区的高温组织。发现在快速的焊接加热情况下奥氏体相亦能全部溶入铁素体相中;在随后的快速冷却中,铁素体相向奥氏体相的转变却是不平衡的。试验结果表明,热影响区高温段的纯铁素体晶界有晶间腐蚀倾向,而奥氏体一铁素体晶界不发生腐蚀并有阻止晶间腐蚀扩展的作用。采取冶金、工艺措施在焊接热影响区获得二次奥氏体相把铁素体晶粒包围起来,形成象似“锁边”形貌的双相组织是提高耐晶间腐蚀能力的有效途径.
In this paper, 00Cr18Ni5Mo3Si2 duplex stainless steel heat-affected zone HAZ transformation characteristics and impact on the performance were discussed. The heat-affected zone structure is reproduced using the welding heat simulation. Adopting the welding heat cycle heating - water quenching method to fix the high temperature structure in the heat affected zone. It is found that the austenite phase can also be completely dissolved into the ferrite phase in the case of rapid welding heating. In the subsequent rapid cooling, the transformation from ferrite phase to austenite phase is unbalanced. The experimental results show that the pure ferrite grain boundaries have a tendency of intergranular corrosion in the heat-affected zone and the austenite-ferrite grain boundaries do not corrode and prevent intergranular corrosion. Adopting metallurgical and technological measures to get secondary austenite grains in the HAZ of heat affected zone to envelop the ferrite grains and form a duplex structure like “lock edge” morphology is an effective way to improve the intergranular corrosion resistance.