表面双尺度结构对304不锈钢的耐磨性和成形性的影响  

Effects of Surface Bimodal Microstructure on Wearing Resistance and Formability of 304 Stainless Steel

作　　者：郑志军[1] 周驰宇 王文熊 高岩[2] 李浩[3] 陈忠斌 ZHENG Zhijun;ZHOU Chiyu;WANG Wenxiong;GAO Yan;LI Hao;CHEN Zhongbin(School of Mechanical &Automotive Engineering,South China University of Technology,Guangzhou 510641,China;School of Materials Science and Engineering,South China University of Technology,Guangzhou 510641,China;Guangdong Inspection and Quarantine Technology Center,Guangzhou 510642,China;Shunde Diwei Stainless Steel Products Co.,LTD.,Shunde 528325,China)

机构地区：[1]华南理工大学机械与汽车工程学院,广州510641 [2]华南理工大学材料科学与工程学院,广州510641 [3]广东出入境检验检疫局,广州510642 [4]佛山市顺德区帝伟不锈钢制品有限公司,顺德528325

出　　处：《中国表面工程》2018年第6期14-21,共8页China Surface Engineering

基　　金：广东省科技计划项目(2015A010105006)~~

摘　　要：首先利用高能喷丸工艺对304不锈钢进行表面纳米化处理,再通过退火处理在表面获得双尺度结构,从而实现耐磨性-成形性间的平衡。通过金相和X射线衍射分析来表征细化层的微观结构,通过横截面的硬度测量和耐磨性实验来表征不锈钢的耐磨性,利用杯突实验和成形极限(FLD)实验来表征不锈钢的成形性。结果表明,0.3 MPa-6 min表面喷丸可以获得平均晶粒尺寸约为36 nm,平均硬度为353 HV0.2,形变诱发马氏体质量分数50.2%,厚度约为125μm的细化层。表面喷丸纳米化不锈钢的耐磨性显著提高,但成形性明显下降。表面喷丸纳米化+650℃退火30 min可在不锈钢表面获得双尺度结构的细化层,其中粗晶部分的平均晶粒尺寸约为1～2μm,体积比约66%;细晶部分的平均晶粒尺寸约为58 nm,体积比为34%。这种双尺度结构的表面细化层兼具高耐磨性和高成形性的特性。The 304 stainless steel(SS) first underwent surface nanocrystallization treatment by high energy shot peeing,and was subsequently annealed to achieve a wearability-formability balance through bi-modal microstructure(BMS) tailoring.The microstructure of specimen was characterized by optical micrograph and X-ray diffraction(XRD).The wear resistance was estimated by means of hardness measurement on the cross-section of specimen and the abrasion resistance test.The formability was measured through the cupping test and forming limit diagrams(FLD).Results show that the surface nanostructured layer on SS with about 125 μm thickness is obtained by shot peening under 0.3 MPa for 6 min,in which the average grain size and hardness are about 36 nm and 353 HV0.2,respectively,and the volume fraction of the deformation-induced martensite is 50.2%.This nano-structured surface offers higher wearing resistance but lower formability.The annealing of surface nanocrystalline SS at 650 ℃ for 30 min produces the BMS consisting 66% coarse grains with an average size of 1~2 μm and 34% nanocrystalline grains with an average size of 58 nm.Consequently,the surface BMS SS presents high wearing resistance and high formability simultaneously.

关 键 词：不锈钢 喷丸 纳米晶 双尺度结构 耐磨性 成形性 

分 类 号：TG668[金属学及工艺—金属切削加工及机床]