Cr_2N沉淀相对2101双相不锈钢焊接接头综合性能的影响  

Effect of precipitation Cr_2N on comprehensive performance of DSS 2101 welded joint

作　　者：孟庆森[1,2] 王皓[1] 胡利方[1] 

机构地区：[1]太原理工大学材料科学与工程学院,太原030024 [2]青岛滨海学院机电学院,青岛255000

出　　处：《焊接学报》2013年第10期105-108,118,共4页Transactions of The China Welding Institution

摘　　要：对经济型2101双相不锈钢焊接接头1 050℃固溶后在700℃进行不同保温时间的时效处理.采用光学显微镜、SEM和TEM观察接头各区域的组织演变,对接头进行低温冲击试验和动电位极化腐蚀试验.结果表明,1 050℃固溶处理改善了接头的组织和性能;700℃时效处理后焊缝和HAZ析出Cr2N沉淀相,随着时效时间延长,沉淀相长大,数量变多并向铁素体内部生长,使接头冲击韧性降低,断口由塑性断裂的韧窝状转变为脆性断裂的解理状;固溶处理试样点蚀发生在铁素体内部,时效处理后点蚀发生在Cr2N周围的二次奥氏体区,时效时间越长,接头的抗点蚀能力越差.Cr2N的析出对接头焊缝区的影响最为显著.Economy DSS 2101 welded joints were aged at700 ℃ for different time after 1 050 ℃ solution-annealed treatment. The organization evolution of each specimen was observed by optical microscopy,SEM and TEM. Low-temperature impact and potentiodynamic polarization corrosion test were carried out on the specimens. The results showed that the joint had good organization and performance after 1 050 ℃ solution-annealed treatment. Precipitation Cr2N nucleated at weld seam and HAZ when aged at 700 ℃ and grew into α-phase with the increasing of aging time,which leaded a serious declination in the impact toughness. The dimple-like ductile fracture changes into cleavage-like brittle fracture. Pitting nucleated preferentially in the α-phase for the solution-annealed specimen,while the initiation of pitting corrosion took place around Cr2N,which located in the newly formed γ2for the aged specimen. The resistance to pitting corrosion decreased continuously with the increasing of aging time. The weld metal is the most sensitive area to Cr2N.

关 键 词：2101双相不锈钢 焊接接头 氮化物沉淀 冲击韧性 抗点蚀性 

分 类 号：TG156[金属学及工艺—热处理]