500℃长期时效对2205不锈钢组织及韧性的影响  

Effect of long-term aging at 500 ℃ on microstructure and toughness of 2205 stainless steel

作　　者：王海波[1] 石树坤[2] 孙青竹[1] 

机构地区：[1]攀枝花学院材料工程学院,四川攀枝花617000 [2]莱芜钢铁集团有限公司,山东莱芜271100

出　　处：《材料热处理学报》2014年第1期135-139,共5页Transactions of Materials and Heat Treatment

摘　　要：借助扫描电镜、透射电镜和示波冲击试验机研究了2205双相不锈钢经1040℃固溶处理40min，500℃下不同时效时间（1—8个月）对其显微组织和韧性的影响。结果表明，经过固溶处理后的不锈钢只有铁素体和奥氏体组成，在500℃进行时效时，显微组织和韧性发生了显著变化。当时效到2个月左右的时候，铁素体相发生了调幅分解，分别产成了富铁铁素体相（α）和富铬铁素体相（α＇），并发现大量的位错结构；5个月时，在铁素体和奥氏体相的的两相晶界出有析出相R相生成并长大，并且析出相的数量达到最大；当时效时间达到8个月时，沉淀析出相变的粗大，数量不再增加，并发现R相聚集成团。随着时效时间的延长，冲击能和韧性大大下降。铁素体的调幅分解和析出相的生成是导致其韧性下降的主要原因。The effect of long-term aging at 500 ℃ on microstructure and toughness of 2205 stainless steel was studied by means of scanning electron microscopey SEM, transmission electron microscopy（TEM） and impact testing machine. The results show that the microstructure of the stainless steel after solution annealing treatment is consisted of only two phases. When the alloy is aged for approximately 2 months at 500 % , Cr-rich α＇-phase and Fe-rich α-phase are formed by spinodal decomposition. When the alloy is aged at 500 ℃ for 5 months, the needle-shape precipitates of R begin to precipitate along the grain boundaries,and the amount of precipitates （R-phase） has a peak. Extending the aging time to 8 months makes the precipitate of R-phase grown and coarsen. Besides, the impact energy and toughness of 2205 stainless steel dramatically decrease with the increase of the aging time. According to the further analysis, the main reason is directly related to the spinodal decomposition of ferrite phase and the generation of precipitation R phase.

关 键 词：2205不锈钢 等温时效 显微组织 调幅分解 R相 

分 类 号：TG142.7[一般工业技术—材料科学与工程]