深冷处理最低温度对9%Ni钢力学性能及逆转奥氏体含量的影响（英文）  

Effect of Minimum Temperature on the Mechanical Properties and Reversed Austenite Content of 9%Ni Steel Subjected to Cryogenic Treatment

作　　者：顾开选[1] 王俊杰[1,2] 张红 郭嘉[1] Gu Kaixuan;Wang Junjie;Zhang Hong;Guo Jia(CAS Key Laboratory of Cryogenics,Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院理化技术研究所低温工程学重点实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《稀有金属材料与工程》2018年第11期3277-3283,共7页Rare Metal Materials and Engineering

基　　金：Beijing Natural Science Foundation(2164072);Youth Innovation Promotion Association of CAS(2016021)

摘　　要：通过实验研究了深冷处理过程中的最低处理温度对9%Ni钢力学性能和逆转奥氏体含量的影响。采用了不同的深冷处理温度和保温时间,并与9%Ni钢新发展起来的热处理工艺淬火、亚稳淬火、回火(QLT)相结合。结果表明,-80和-110℃的冷处理对9%Ni钢的力学性能和逆转奥氏体含量没有明显影响。然而,-140℃保温24 h的深冷处理能够提高9%Ni钢的冲击韧性,其机理主要在于深冷处理使得块状的逆转奥氏体转变为条状。此外,-140℃深冷处理通过等温马氏体转变使得逆转奥氏体的含量减少。-196℃保温24 h深冷处理增加了逆转奥氏体的含量,同时细化了二次马氏体板条组织,从而使得9%Ni钢的室温和低温冲击韧性均得到提高。其机理主要是由于深冷-196℃深冷处理促使了超细碳化物的析出,同时增加了组织内应力,从而为逆转奥氏体在回火过程中的形核提供了更多了形核位置。The effect of minimum temperature on the mechanical properties and reversed austenite content of 9%Ni steel subjected to cryogenic treatment was experimentally investigated.Cryogenic treatment with different temperatures and soaking time were conducted by combining with the newly developed quenching,lamellarizing and tempering (QLT)heat treatment of 9% Ni steel. The results show that the cryogenic treatment at -80 and -110℃ has no obvious influence on the reversed austenite content and mechanical properties of 9%Ni steel.However,the room temperature impact toughness is improved by cryogenic treatment at -140℃ for 24h,which is attributed to the modification in the reversed austenite morphology from bulks into strips.The volume fraction of the reversed austenite decreases slightly due to the isothermal martensitic transformation at -140℃.Cryogenic treatment at -196℃ for 24h increases the volume fraction of reversed austenite and refines the secondary martensite lath,thereby improving both the room temperature impact toughness and cryogenic ductility.The observed results are mainly due to the precipitation of ultra-fine carbides and the increase of internal stress during cryogenic treatment,which provides more nucleation sites for the reversed austenite in the process of tempering.

关 键 词：9%NI钢 深冷处理 逆转奥氏体 机械性能 微观组织 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG161[金属学及工艺—金属材料]