热锻模药芯焊丝电弧增材制造熔覆层摩擦磨损性能

Tribological Properties of Hot Forging Die Flux Cored Wire Cladding Layer by Arc Additive Manufacturing

目的研究工艺参数、搭接区域对熔覆层组织和性能的影响以及磨损性能的各向异性。方法在H13基板上分别制备单道多层和多道多层熔覆层。对熔覆试样进行2次高温回火,分别对单道多层和多道多层试样的搭接区与非搭接区进行往复磨损实验。研究多道多层试样平行和垂直于扫描方向熔覆层的磨损性能,结合金相组织,讨论磨损性能与组织的关系。结果熔覆层的组织为回火马氏体+残余奥氏体+粒状碳化物。与扫描速度8 mm/s相比,扫描速度10 mm/s时熔覆层的残余奥氏体含量更高、硬度更低、磨损轮廓更大。与非搭接区相比,搭接区组织更为粗大、摩擦因数表现更不稳定、磨损轮廓更大。与平行扫描方向相比,垂直于扫描方向的试样摩擦因数更稳定、磨损轮廓尺寸更小。结论扫描速度8 mm/s时的单道多层熔覆层的磨损性能优于扫描速度10 mm/s时的;多道多层熔覆层搭接区的磨损性能比非搭接区的磨损性能差,与平行扫描方向相比,垂直扫描方向的熔覆层磨损性能表现较佳。

The work aims to study the effects of process parameters and lap area on the microstructure and properties of the cladding layer and the anisotropy of wear properties.Single-pass multilayer and multi-pass multilayer cladding layers were prepared on H13 substrate,respectively.The cladding samples were tempered twice at high temperature and reciprocating wear tests were carried out on the lap and non-lap areas of single-pass multilayer and multi-pass multilayer samples respectively.The wear properties of the cladding layers in parallel and perpendicular to the scanning direction were studied.The relationship between wear properties and microstructure was discussed by metallographic analysis.The microstructure of the cladding layers was tempered martensite+residual austenite+granular carbide.The cladding layers at a scanning speed of 10 mm/s had higher residual austenite content,lower hardness and larger wear profile than that at 8 mm/s.Compared with the non-lap area,the lap area had coarse structure,unstable friction coefficient and large wear profile.The friction coefficient of sample perpendicular to the scanning direction was more stable than that of sample in parallel to the scanning direction,and the wear profile size was smaller.The wear properties of the single-pass multilayer cladding layer at a scanning speed of 8 mm/s are better than that at a scanning speed of 10 mm/s,the wear properties of the lap area are slightly worse than that of the non-lap area,and the wear properties of the cladding layer perpendicular to the scanning direction are better than that of the cladding layer in parallel to the scanning direction.