稀土元素对430钢500℃等离子体渗氮的影响  

Effect of rare earth elements on plasma nitriding of 430 steel at 500℃

作　　者：洪霖 由园 韩廷杰 王逸凡 盛文萍 王妍 王美懿 顾峰 王超会 程伟东 HONG Lin;YOU Yuan;HAN Ting-jie;WANG Yi-fan;SHENG Wen-ping;WANG Yan;WANG Mei-yi;GU Feng;WANG Chao-hui;CHENG Wei-dong(School of Materials Science and Engineering,Heilongjiang Provincial Key Laboratory of Polymeric Composition Materials,Qiqihar University,Heilongjiang Qiqihar 161006,China)

机构地区：[1]齐齐哈尔大学材料科学与工程学院,黑龙江省聚合物基复合材料重点实验室,黑龙江齐齐哈尔161006

出　　处：《齐齐哈尔大学学报（自然科学版）》2023年第4期47-51,共5页Journal of Qiqihar University(Natural Science Edition)

基　　金：国家自然科学基金(51401113);黑龙江省自然科学基金(E2016069);黑龙江省重点研发计划指导类项目(GZ20210034);黑龙江省聚合物基复合材料重点实验室开放课题(CLKFKT2021B7);2022年齐齐哈尔大学大学生创新创业训练计划项目(x202210232075)。

摘　　要：对430钢500℃氨气和氨气稀土条件渗氮4 h和8 h后的渗氮层进行了对比。表征了渗氮层截面显微组织、显微硬度、相组成以及耐蚀性。渗氮层由化合物层及扩散层组成,4 h渗氮后总厚度分别79.6μm和129.0μm,8 h渗氮后总厚度分别为88.1μm和152.7μm;8 h氨气渗氮后其渗氮层的表面硬度为1032.5 HV0.05,加入稀土后8 h氨气渗氮后渗氮层的表面硬度达到1086.0 HV0.05,渗氮后的最高硬度为1189 HV0.05,远高于430钢的基体硬度(173.5 HV0.05)。渗氮后的主要相是ε-Fe2-3N相,次要相为Fe4N相,在加入稀土后ε-Fe2-3N相和Fe4N的峰面积增加,析出的氮化物更多,且加入稀土后晶粒尺寸变小,晶粒尺寸与硬度有着负相关的关系,且晶粒尺寸变小,组织细化,晶粒细化增大晶界,晶界面的缺陷增加,有利于N原子的扩散,对渗氮有着催进作用。Plasma nitriding was carried out on 430 steel in an atmosphere of NH3 with and without RE at 500℃for 4,8 h.The nitrided layer's cross section microstructure,microhardness,phase composition,and corrosion resistance were characterized.The nitrided layer was composed of a compound layer and a diffusion layer.The total thicknesses of the nitrided layer after 4 h with and without RE were 79.6μm and 129.0μm.After 8 h with and without RE of nitriding,the nitrided layer thickness was 88.1μm and 152.7μm.The surface hardness of the nitrided layer was 1032.5 HV0.05 after 8 h of nitriding.And after 8 h of RE nitriding,the surface hardness of the nitrided layer increased to 1086.0 HV0.05,with a maximum hardness of 1189 HV0.05,which was significantly higher than the matrix hardness of 430 steel(173.5 HV0.05).The main phase after nitriding was theε-Fe2-3N phase,with the secondary phase being the Fe4N phase.After the addition of RE,more nitrides were generated after nitriding,the peak areas ofε-Fe2-3N and Fe4N phases increased and the average grain size decreased.Grain size had a negative correlation with hardness,and decrease grain size resulted in microstructure refinement and increased grain boundary.The increase in defects on the grain interface aided N atom diffusion,resulting in an accelerated effect on nitriding.

关 键 词：430钢 离子渗氮 显微硬度 稀土 

分 类 号：TG161[金属学及工艺—热处理]