300M钢基体上高速火焰喷涂WC-17Co和WC-10Co4Cr涂层的疲劳和抗盐雾腐蚀性能

Characterizations of Fatigue and Salt Spray Corrosion Resistance of HVAF Sprayed WC-17Co and WC-10Co4Cr Coatings on the Substrate of 300M Steel

摘要:

以涂层在飞机起落架的应用作为研究背景，在300M超高强钢基体上对替代电镀硬铬的两种高速火焰喷涂WC- 17Co和WC-10Co4Cr涂层的疲劳和抗中性盐雾腐蚀性能进行了研究。结果表明，两种有涂层的300M钢的疲劳寿命均高于无涂层300M钢，如考虑扣除涂层承受载荷，有涂层的300M钢与无涂层300M钢的疲劳寿命相当。喷砂镶嵌在基体表面的刚玉砂粒导致有WC-10Co4Cr涂层的疲劳寿命低于有WC-17Co涂层的300M钢。两种涂层对基体的疲劳性能都没有负面影响；两种涂层都提高了300M钢的抗盐雾腐蚀性能，但有WC-10Co4Cr涂层的300M钢表现出更好的抗盐雾腐蚀性能。综合比较两种涂层的性能，高速火焰喷涂WC-10Co4Cr涂层是更好的电镀铬替代涂层。

Abstract:

The fatigue and neutral salt spray corrosion resistance for bare and coated high strength steel were investigated in this paper. The results indicated that WC-17Co and WC-10Co4Cr coatings led to significant increase of fatigue resistance compared with the substrate. There were also comparably similar cycles to failure for the bare and the coated substrates even though the stress which was WC-based coatings shouldered was taken into account. The lower cycles to the failure for WC-10Co4Cr coated substrate than those for WC-17Co coated substrate were attributed to embeding of blasted alumina grit on the substrate surface, which resulted in the great decrease of the cycles to failure. Both WC coatings produced no negative effect on the fatigue performance of 300M steel. The neutral salt spray corrosion resistance for 300M steel substrate was significantly improved after coating process, especially for WC-10Co4Cr coating. As a conclusion, HVAF WC-10Co4Cr coated high strength steel exhibited better performances in both fatigue and neutral salt spray corrosion resistance than that of the substrate, and WC-10Co4Cr coating was a better candidate to chrome plating.