Q245钢表面等离子堆焊Fe-Cr-Ti-C层的组织与耐磨性能

Microstructure and Wear Resistance of Iron-Chromium-Titanium-Carbon Plasma Surfacing Welding Coatings on Plain Carbon Steel

为了研制一种铁基耐磨复合材料,采用等离子堆焊技术制备了3组Fe-Cr-Ti-C系合金堆焊层。在MLS-23型湿砂橡胶轮式磨损试验机上进行磨粒磨损试验,采用JSM-6360LV型扫描电子显微镜(SEM)和布鲁克D8型衍射仪等技术,观察了堆焊层的组织、碳化物形貌及磨损形貌,探讨了磨损机理。结果表明:随着堆焊层中Ti含量的提高,其组织由奥氏体加铁素体向马氏体转变,碳化物Ti C及M7C3等硬质相的数量逐渐增多、且分布弥散均匀;当Ti含量为9.67%时,Ti C和M7C3硬质相均匀弥散分布在具有较强韧性的板条马氏体中,堆焊层显现出优良的耐磨损性能。

Three Fe-based wear-resistant composite coatings with different composition,denoted as FeCr-Ti-C,were prepared on Q245 steel substrate by plasma surfacing welding.The abrasive wear behavior of as- prepared Fe-Cr-Ti-C surfacing coatings was evaluated with an MLS-23 wet rubber-wheel abrasive wear tester.The phase structure,carbide morphology and worn surface morphology of the surfacing coatings were analyzed by scanning electron microscopy and X-ray diffraction,and the wear mechanisms of the composite coatings were then discussed.Results indicated that with increasing Ti content of the surfacing coatings,the phase species of the coatings were transformed from austenite plus ferrite to martensite,while the volume fraction of M_7C_3 and TiC hard carbides increased and they tended to be distributed uniformly therewith.When the Ti content was 9.67%(mass fraction),TiC and M_7C_3 hard phases were dispersed uniformly in lath- like martensite matrix with higher strength and toughness,which helped to effectively improve the wear resistance of the surfacing coatings.