机械液压杆的选材与耐蚀性能研究

Material Selection and Corrosion Resistance of Mechanical Hydraulic Rods

选用4种不同类型的机械液压杆为试验对象,对比分析了不同时间盐雾/干/湿交替循环腐蚀试验条件下试样的宏观和微观腐蚀形貌、腐蚀速率和物相组成。测试了不同循环腐蚀时间下机械液压杆的腐蚀速率。结果表明,0Cr17Ni4Cu4Nb马氏体不锈钢的耐腐蚀性能最好,其次为302奥氏体不锈钢,而40Cr中碳调质钢的耐腐蚀性能最差;4种机械液压杆的耐腐蚀性能从低至高依次为:40Cr中碳调质钢<18Cr2Ni4合金钢<302奥氏体不锈钢<0Cr17Ni4Cu4Nb马氏体不锈钢;5 000 h盐雾/干/湿交替循环腐蚀试验后机械液压杆的表面腐蚀形貌观察结果与腐蚀速率和点腐蚀评价结果一致。

With the four different types of mechanical hydraulic rods as test objects, the macro and micro corrosion morphologies, corrosion rates and phase compositions of the samples under different salt/dry/wet cyclic corrosion tests were compared. The test results of corrosion rate of mechanical hydraulic rods under different cyclic corrosion time show that martensitic stainless steel 0Cr17Ni4Cu4Nb has the best corrosion resistance, followed by 302 austenitic stainless steel, and the corrosion resistance of carbon steel 40Cr is the worst. Point corrosion evaluation results show that the corrosion resistance of the four kinds of mechanical hydraulic rods from low to high are 40Cr medium-carbon quenched and tempered steel, 18Cr2Ni4 steel, 302 austenitic stainless steel and 0Cr17Ni4Cu4Nb martensitic stainless steel. The results of surface corrosion morphologies of mechanical hydraulic rods after corrosion for 5 000 h in the salt spray/dry/wet alternate cycle condition are consistent with the results from the corrosion rate and point corrosion evaluation.