S280新型超高强不锈钢中一种新析出相研究  

New Phase Precipitated from the New Type of Ultrahigh Strength Stainless Steel S280

作　　者：钟锦岩 张业勤 韩雅芳 Zhong Jinyan;Zhang Yeqin;Han Yafang(Beihang University,Beijing 100191,China;Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]北京航空航天大学,北京100191 [2]北京航空材料研究院,北京100095

出　　处：《稀有金属材料与工程》2019年第1期116-122,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51171023)

摘　　要：通过热处理工艺实验确定了超高强度不锈钢S280合适的热处理工艺(1080℃,保温1 h,油冷;-73℃,2 h,空气中回到室温;540℃,4 h,空冷)。S280钢热处理后,强度大于1900 MPa,K_(1C)大于90 MPa·m^(1/2)。利用透射电子显微镜和高分辨电子显微镜研究了540和600℃时效态的S280新型超高强度不锈钢微观组织结构。结果表明:S280钢540℃时效状态,在高密度位错的板条状马氏体基体上析出弥散细小的强化相,一种是已为很多研究报道的超高强度钢中强化相Fe_2Mo^([1]),另一种析出相是Cr_2C,目前还未见相关报道。本研究测定了Cr_2C与马氏体的晶体学取向关系为:(110) _M//(121)_(Cr_2C),[111]M//[111]_(Cr_2C)。S280钢在600℃时效态也析出这2种Cr_2C和Fe_2Mo相,与540℃时效态相比,只是其有所长大。利用X射线能谱分析法对Cr_2C析出相进行了分析,结果表明,Cr_2C析出相中Cr和Mo的含量较高。By heat treatment process experiments and mechanical tests, the appropriate heat treatment process of S280 steel(heating to1080 ℃,holding for 1 h, and quenching in oil, cooling to-73 ℃, holding for 2 h, and warming in air to room temperature and then heatingto 540 ℃, holding for 4 h, and cooling in air) was found in this research. After the appropriate heat treatment process, S280 steel can getgood comprehensive performance, with the strength of 1900 MPa, and K1C of 90 MPa·m1/2. The microstructures of new ultrahigh strengthstainless steel S280 after thermal ageing at 540 ℃ and 600 ℃ was investigated by optical microscopy, transmission electron microscopy(TEM) and high resolution electron microscopy(HREM). The results show that the S280 steel aged at 540 ℃ has desirablemicrostructures, which is fine lath martensite matrix with high density dislocation and finely dispersed precipitate strengthening phase, andfilm-like reversed austenite precipitated from the boundary of martensite. The strengthening phases of the steel include Fe2Mo[1], Fe3C andCr2C. There is no related report about that Cr2C precipitated from ultrahigh strength steel as a strengthening phase. And thecrystallographic orientation relationship between Cr2C and matrix was measured:(110)M//(121)Cr2C,[111]M//[111]Cr2C. The steel aged at 600 ℃ have the same precipitated phases Cr2C and Fe2Mo. and they are relatively bigger than that of sample aged at 540 ℃. Thestrengthening phases of S280 steel have high contents of Cr and Co analyzed by energy spectrum analysis(EDS).

关 键 词：S280新型超高强度不锈钢 微观组织结构 析出相 Cr2C 

分 类 号：TG142.1[一般工业技术—材料科学与工程]