300M钢表面冷喷涂锌镍复合涂层性能研究

目的 研究300M高强钢表面的冷喷涂锌镍复合涂层的涂层性能.方法 采用机械混合的方式将锌粉和镍粉进行混合,利用低温气动喷涂技术在300M高强钢表面制备锌镍复合涂层,采用扫描电子显微镜、能量色散谱和显微硬度测试仪研究涂层的微观组织结构.采用普通中性盐雾加速实验、涂层破损盐雾加速试验及户外暴晒试验,对冷喷涂锌镍涂层的抗腐蚀性能进行综合评价.考核冷喷涂对300M钢基材疲劳性能的影响.结果 根据SEM的表面及截面图片分析,冷啧涂锌镍复合涂层十分致密,且无孔隙及裂纹,涂层的孔隙率平均为0.4％,结合强度40 MPa左右.根据EDS结果分析,锌镍复合涂层中锌的质量分数为85％左右,镍的质量分数为15％左右.锌镍复合涂层的显微硬度为70.8HV0.49.锌镍复合涂层中镍粒子的强化作用,提高了涂层的硬度.冷喷涂锌镍复合涂层具有非常好的抗腐蚀性能,盐雾实验超过770h,即使涂层破损也可以达到600h.户外暴晒实验12个月表面无明显腐蚀,并且冷喷涂对300M钢基材的疲劳性能没有影响.结论 冷喷涂锌镍复合涂层作为抗腐蚀涂层,可以对300M高强钢提供保护.

Properties of Cold Spray Zn/Ni Coatings on 300M Steel

Objective To study the performance of Zn/Ni composite coatings on 300M high-strength steel surface, which were deposited by cold gas dynamic spray. Methods The coating was sprayed by Zn and Ni physical mixture powder on 300M high-strength steel surface. The morphology and microstructure of the coatings were analyzed by the SEM images, EDS and microhardness tester. The corrosion resistance of Zn/Ni coatings was comprehensively investigated by neutral salt-spray test, coating furcated test and atmospheric exposure test. The effect of cold spray on the fatigue property of 300M steel substrate was tested. Results The surface and cross-section SEM images indicated that the cold sprayed Zn/Ni composite coatings were very compact, without pores and cracks, the porosity of Zn/Ni coatings was 0.4% and the bonding strength was 40 MPa. The EDS analysis result showed that the mass fractions of Zn and Ni in the Zn/Ni composite coatings were about 85% and 15%, respectively. The microhardness of Zn/Ni coatings was 70.8HV0.49, this is because the hardness of the coatings was improved by the strengthening effect of Ni in the Zn/Ni coatings. Cold sprayed Zn/Ni composite coatings had very good corrosion resistance. The salt spray result of Zn/Ni coatings could reach 770 h, and it could reach 600 h even at coatings failure. No obvious corrosion was observed on the surface after 12-month atmospheric exposure test, and cold spray had no influence on the fatigue property of 300M steel substrate. Conclusion Cold sprayed Zn/Ni composite coatings could be used as efficient corrosion-resistant coatings on 300M high strength steel surfaces.