冷喷涂镍涂层在不锈钢焊点腐蚀防护上的应用研究

目的 研究冷喷涂镍涂层对不锈钢焊点腐蚀行为的影响，为提高不锈钢焊接结构件的耐腐蚀性能提供依据。方法 采用冷喷涂技术在316L不锈钢电阻点焊结构件表面制备纯镍涂层，在金相组织、酸性盐雾腐蚀性能等检测分析基础上，研究不锈钢焊点在有涂层和无涂层条件下的腐蚀行为。结果 采用冷喷涂技术在不锈钢焊点表面制备出了孔隙率不大于0.5%的高致密纯镍涂层，带有涂层的不锈钢点焊结构件经过96 h酸性盐雾试验后，未发生腐蚀。结论 不锈钢表面钝化膜在点焊过程中发生破坏，基体裸露在腐蚀介质中，导致焊点区域发生腐蚀。在表面制备高致密镍涂层后，通过高耐蚀涂层对焊点进行屏蔽防护，有效提高其耐腐蚀性能，满足了某装备不锈钢结构件在酸性盐雾条件下的使用要求。

Application of Cold Sprayed Nickel Coating on Corrosion Prevention of Stainless Steel Solder Joint

The work aims to study the effect of cold sprayed nickel coating on the corrosion behavior of stainless steel solder joints, and provide a basis for improving the corrosion resistance of stainless steel welded structural parts. Cold spraying technology was used to prepare pure nickel coating on the surface of 316L stainless steel spot welding structural parts. Based on the detection and analysis of metallographic structure and acid salt spray corrosion performance, the corrosion behavior of the stainless steel solder joints was studied under coated and uncoated conditions. A high-density pure nickel coating with a porosity of not more than 0.5% was prepared on the surface of stainless steel welding joints by cold spray technology. After 96 hours of acid salt spray test, the coated stainless steel spot welding structure had no corrosion. The passivation film on the surface of stainless steel is damaged during the spot welding process, and the substrate is exposed to the corrosive medium, which leads to corrosion in the solder joint area. After the high-density nickel coating is prepared on the surface, the solder joint is shielded and protected by a high corrosion-resistant coating, effectively improving its corrosion resistance, and meeting the requirements on the use of a certain equipment stainless steel structure under acid salt spray conditions.