摘要
采用高速电弧喷涂技术及钨极氩弧重熔技术分别制备Fe-Cr-B喷涂层及其重熔层,采用X射线衍射仪、金相显微镜、X射线残余应力测试仪、显微硬度仪、动载磨料磨损试验机、扫描电子显微镜分别对喷涂试样及重熔试样的相结构、微观组织、残余应力、纵截面硬度、耐磨性及磨损表面形貌进行观察与测试。结果表明,重熔处理后,电弧喷涂Fe-Cr-B涂层的组成由Fe基非晶和硼化物相转为Cr_2B、(Cr,Fe)_2B、α-Fe相,涂层与基体由机械结合转为冶金结合,重熔试样由表层至基体的显微组织分别是初生硼化物以及共晶组织、共晶硼化物+马氏体+奥氏体、初生奥氏体以及共晶组织、热影响区组织。重熔处理后,涂层显微硬度由689 HV0.1上升为960 HV0.1,磨损失重率由0.088 g/(cm^2·min^(-1))降为0.004 6 g/(cm^2·min^(-1))。喷涂层的磨粒磨损机制主要是微断裂,重熔层的磨粒磨损机制主要是变形磨损和微切削。
Fe-Cr-B spray coatings and its remelted layers were deposited by high velocity arc spraying （HVAS） and tungsten inert gas arc remelting（TIG remelting）, respectively. The phase structures, microstructures, residual stress, microhardness, wear resistance and worn morphology were analyzed and tested by X-ray diffraction （XRD）, optical microscopy （OM）, X-ray diffraction residual stress tester, microhardness tester, impact abrasion tester and scanning electron microscopy （SEM）, respectively. The results show that, before and after being remelted, the phase structure is transformed from amorphous and boride phase to Cr2B, （Cr, Fe）2B and α-Fe phase. The coating-substrate interface changes flom mechanical interlock to chemical metallurgical bonding. The microstructures of the remelted specimen from the surface to the substrate are primary boride and eutectic structure, eutectic structure, primary austenite and eutectic structure, and heat affected zone structure, respectively. Thus, the performance difference between the remelted layers and the substrate is effectively relieved by this gradient structure. Before and after being remelted, the microhardness rise from 689 HV0.1 to 9,60 HV0.1, and the worn mass loss values are reduced from 0.088 g/（cm^2·min^-1） to 0.004 6 g/（cm2^2·min^-1）. Micro-fracture is the predominant wear mechanisms for the spray coatings. Deformation wear and micro-cutting are the predominant wear mechanisms for the remelted layers.
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2016年第5期102-108,共7页
China Surface Engineering
关键词
钨极氩弧重熔
高速电弧喷涂
Fe-Cr-B
动载磨损
tungsten inert gas arc remelting
high velocity arc spraying （HVAS）
Fe-Cr-B
dynamic wear
