Desulfurization Slurry Circulating Pump Impeller Surface Corrosion Resistant WC-Co Coatings

The serious corrosion and wear problems of slurry circulating pump impeller surfaceof the desulphurization device severely impact the running of gas desulphurization systemand maybe takes huge economic loss. Many experts have been carrying out researchesabout this subject and found that using supersonic flame spraying(HVOF) to spray WC-Cocoating is a very effective way in the slurry circulating pump impeller surface. Therefore,there has important practical significance on its pilot study.Three coating WC-12Co, WC-17Co and WC-10Co-4Cr were prepared using HVOFtechnology, the coating structure, strength, hardness and wear and corrosion were studiedcompared with316stainless steel, the optical microscope(OM), scanning electronmicroscopy(SEM), energy dispersive spectroscopy(EDS), X-ray diffraction(XRD) wereused to analysis the test results in this paper.The test results show that: there are three main phase structure of the coating as WC,W2C, Co and Co6W6C solid solution, carbides were into a dispersed state; theremicrohardness were1122,1061,1313HV0.1, the bonding strength were58,62,65MPa,cohensive strength were165.9,194.6,216.3MPa, sliding wear weight loss of the threecoating are very small, much smaller than the316stainless steel, explained the sliding wearresistance performance of the coatings were excellent which the WC-12Co has lowestweight loss, WC-10Co-4Cr coating the next best; WC-10Co-4Cr coating wear scarminimum abrasion performance, WC-12Co coating followed according to the three coatedabrasive weightlessness and morphplogy.