等离子弧堆焊铁基熔覆层组织结构与磨损行为

Microstructure and wear behavior of Fe-based coating prepared by plasma transferred arc-welding

设计开发了一种铁基(含Cr,Mo,C,B,Si,Mn等元素)多元合金粉末,采用等离子弧堆焊(PTAW)技术在AISI304L不锈钢表面制备相应熔覆层,通过XRD,SEM,EDS及磨粒磨损试验机等对熔覆层微观组织结构和磨损行为等进行表征,并与传统NiCrBSi和NiCrBSi+25%WC粉末的PTAW熔覆层进行了对比研究.结果表明,所设计的铁基合金熔覆层成形良好,基体组织由Fe-Cr固溶体相与γ-Fe相构成,其间包裹着大量弥散分布的富钼硼化物和M23(B,C)6硬质相,对熔覆层组织能够起到有效的支撑和强化作用.铁基熔覆层的宏观硬度平均值高达64.2HRC,其相对耐磨性明显优于NiCrBSi+25%WC熔覆层,并达到NiCrBSi熔覆层的8倍以上.

A new Fe-based alloy powder was designed to prepare coatings by plasma transferred arc-welding( PTAW)process on AISI304L stainless steel substrate. The microstructure and wear behavior of the relative coating were detected by XRD,SEM and a rubber wheel abrasive testing machine respectively,in comparison with that of the traditional NiCrBSi and NiCrBSi +25% WC coatings. The results show that the matrix of Fe-based coating consists of Fe-Cr solid solution and γ-Fe phase,surrounded by numerous dispersed Mo-rich borides and M23( B,C)6hard phases,which contribute to support and strengthen the coating organization. The Fe-based coating exhibits high average hardness of 64. 2 HRC,and excellent wear resistance which is better of that of the NiCrBSi + 25% WC coating and exceeds 8times of that of the NiCrBSi coating.