ZG35Cr25Ni12NNbRE钢中黑斑组织的成因探讨  

DISCUSSION ON FORMATION MECHANISM OF BLACK SPECKLE MICROSTRUCTURE IN AN AUSTENITIC HEAT-RESISTANT CAST STEEL ZG35Cr25Ni12NNbRE

作　　者：刘江文[1] 罗承萍[1] 肖晓玲[1] 陈和兴[2] 

机构地区：[1]华南理工大学,广州510641 [2]广州有色金属研究院,广州5610650

出　　处：《理化检验（物理分册）》2003年第1期25-27,61,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

基　　金：广东省自然科学基金资助 ( 980 494)

摘　　要：ZG35Cr2 5Ni12奥氏体耐热铸钢经固溶时效后的显微组织由初晶奥氏体、共晶碳化物 ,以及在奥氏体基体上时效析出的二次碳化物组成 ;使用 3.5a(年 )后二次碳化物增多 ,共晶碳化物附近的“无析出区”消失 ,并在许多共晶碳化物内部形成黑斑组织。研究表明 ,黑斑组织是富含稀土元素的氮碳化物ε (Cr ,Fe) 2 (N ,C)相 。The microstructure of an austenitic heat-resistant cast steel ZG35Cr25Ni12NNbRE containing trace N, Nb and Re after solution treatment at 1100℃ and ageing at 600℃ for 6hr consists of M_ 23C_6 eutectic carbide, preliminary dendritic austenite, and secondary carbide M_ 23C_6 precipitated in austenite. After the steel had been serviced for 3.5 years, the precipitate free zone (PFZ) near by eutectic carbides has disappeared and black speckle microstructure formed in eutectic carbide. The black speckle microstructure were identified as ε phase (Cr,Fe)_2(C,N) in which enriched rare earth elements, and this kind of ε phase was gradually formed because of depletion of eutectic carbide while the steel was in service for a long time at rather high temperature.

关 键 词：ZG35Cr25Ni12NNbRE钢 黑斑组织 成因 奥氏体耐热钢 Ε相 碳化物 组织演变 

分 类 号：TG142.73[一般工业技术—材料科学与工程]