热模拟2205DSS焊接HAZ的点蚀实验研究

采用热模拟法模拟焊接热过程,研究了2205双相不锈钢(DSS)的模拟焊接粗晶区的耐点蚀性能和金相组织的关系,探讨了冷却时间t8/5对模拟热影响区(HAZ)组织与点蚀性能的影响.结果表明:冷却时间t8/5对组织及点蚀性能有较大的影响,随冷却时间t8/5的增加,铁素体含量减少,奥氏体含量增加,模拟HAZ的点蚀率和点蚀相对面积降低,但仍大于母材,而最大点蚀深度增大,但低于母材.当冷却时间t8/5为100s左右时,模拟HAZ的抗点蚀性能接近母材的抗点蚀性能.

Pitting Corrosion Property of Simulated Welding HAZ in 2205DDS

The relationship of the microstructures and pitting corrosion property of simulated welding heat affected zone(HAZ) in 2205 duplex stainless steel was investigated using thermal simulator and pitting corrosion testing.The effects of cooling time on the pitting corrosion property of simulated HAZ were studied at the same time.The results showed that the cooling time had influences on the pitting corrosion property of the simulated HAZ,that the ferrite content decreased and precipitate of carbide and nitride in ferrite increases as increasing cooling time,that pitting corrosion rate and pitting corrosion area ratio were higher in simulated HAZ than in base metal and decreased with the increase of the cooling time,that the maximum pitting corrosion depth was lower in simulated HAZ than that in base metal and increases with the cooling time t_(8/5),and that the pitting corrosion property of the simulated HAZ was the same as base metal when the cooling time was about 100s.