WC含量对Stellite6激光熔覆涂层耐液态铅铋腐蚀性能的影响

Influence of WC content on corrosion resistance of Stellite 6 laser cladding coating to liquid lead and bismuth

为提高316L不锈钢耐高速流液态铅铋腐蚀能力,采用激光熔覆方法,通过在Stellite6合金中添加不同比重的WC制备熔覆层,将加工好的试样放进400℃的高温铅铋熔融炉进行500 h高速流实验,相对流速设定为3.23 m/s。使用SEM、XRD、EDS、OM和激光共聚焦显微镜观察了熔覆层腐蚀前后的微观组织和表面形貌,结果表明:随着WC含量增加,熔覆层的硬度值也逐渐增加,当WC添加量在10%时,耐磨性最好,表面粗糙度值最低为33.6μm;不同WC含量的熔覆层均能够有效地提升耐蚀性能,当WC添加量在10%时,渗氧层的深度最小,为2.8μm。

In order to improve the corrosion resistance of 316 L stainless steel to high speed liquid lead-bi corrosion, the laser cladding method was adopted. The cladding layer was prepared by adding WC of different proportions to the Stellite6 alloy. And the processed samples were put into a high-temperature lead-bi melting furnace at 400 ℃ for 500 h high-speed flow experiment. The relative velocity was set to 3.23 m/s. SEM, XRD, EDS, OM and laser confocal microscope were used to observe the microstructure and surface morphology of the cladding layer before and after corrosion. The results show that with the increase of WC content, the hardness value of the cladding layer also increased gradually. When the addition of WC was 10%, the wear resistance was the best, and the surface roughness value was the lowest 33.6 μm. The cladding layers with different WC contents could effectively improve the corrosion resistance. When the WC content was 10%, the minimum depth of the oozing layer was 2.8 μm.