利用等离子弧堆焊获得铁基合金+碳化钨硬质合金的复合堆焊层

Obtaining Composite Deposits Conslstingof Fe-base Alloy+WC Cemented Carbide Particles Under PTA

利用新研制的外送碳化钨等离子弧焊枪系统 ,对F32 1铁基合金粉末和机械破碎的碳化钨硬质合金颗粒进行了堆焊 ,获得的复合堆焊层碳化钨合金颗粒分布均匀 ,堆焊层缺陷率低 ,焊道成型良好 ,碳化钨合金颗粒的质量分数可达 40 %～ 42 % ,堆焊后的碳化钨合金颗粒硬度值仍保持了原有的高硬度 ,颗粒表层重熔量小 ,合金元素扩散率低 ,获得的堆焊层胎体组织为马氏体 +残余奥氏体 +共晶 (马氏体 +碳化物 ) ;碳化钨合金颗粒周围鱼骨状共晶没有扩散到胎体马氏体中 ,避免了复合堆焊层的整体脆化。试验对堆焊层的平均孔隙缺陷率进行了测算 ,测算结果为碳化钨合金颗粒平均孔隙缺陷率低于 1.5 % ,并对裂纹。

Composite deposits consisting of Fe-base alloy F321 powder and WC-Co cemented carbide particles are obtained with a new developed PTA torch that transports WC alloy particles outside the arc transportation. In deposits, WC alloy particles are kept equispaced. These deposits have low defect rates and good external appearance. WC alloy particles content is limited to 40-42% wt in the deposit, and these particles exhibit high hardness as that before surfacing. Surface of WC alloy particles exhibit few refusion and embrittlement-free of deposited layer with few alloys diffusivity, deposit matrixes have a microstructure of martensite + retained austenite + eutectic. Average rate of the deposit defect examined is below 1.5%. The causation and situation of microcracks and voids are analysed.