热处理对Ni-P镀层耐硫酸露点腐蚀性能的影响  

Effect of heat treatment on sulfuric acid dew point corrosion resistance of Ni-P coating

作　　者：常季 陈吉[1] 黄澳 

机构地区：[1]辽宁石油化工大学机械工程学院,辽宁抚顺113001 [2]楚天华通医药设备有限公司,吉林长春130507

出　　处：《金属热处理》2017年第2期175-179,共5页Heat Treatment of Metals

基　　金：辽宁省自然科学基金(201202127)

摘　　要：在20R钢表面化学镀Ni-P合金镀层,结果表明:制备的镀层表面平整致密无裂纹,P含量为10.72%,属于高磷非晶镀层。对镀层热处理后的结构、表面形貌、结合强度等性能进行了测试分析,发现Ni-P镀层经200℃热处理后仍保持非晶态结构并且结合强度更好,升温至300℃后开始析出Ni_3P相,镀层转化为混晶态结构。采用电化学试验方法研究经200℃热处理后Ni-P镀层及常用钢材20R、ND钢和316L不锈钢的耐蚀性,发现Ni-P镀层相对于20R、ND钢和316L不锈钢在5%硫酸溶液中的自腐蚀电位更高,为-234 m V,自腐蚀电流密度更小,为3.8687×10^(-6)A·cm^(-2),电荷转移电阻更大,为954.9Ω·cm^(-2),体现了更好的抗硫酸腐蚀性能;对四种材质在60℃不同浓度硫酸溶液中进行实验室均匀腐蚀试验,它们的年腐蚀率排序为20R?ND?Ni-P>316L。Electroless Ni-P alloy coating on 20 R steel surface was prepared.The test results show that the coating is smooth and compact without cracking,and P content is 10.72%,belonging to high phosphorus amorphous coating.Structure.surface morphology,bonding strength and other properties of the coating were tested after heat treatment.It is found that the Ni-P coating after 200℃ heat treatment remains amorphous structure and its bonding strength is enhanced.When the coating is heat treated at 300℃,it starts to precipitate Ni3P phase and becomes mixed crystal structure.Electrochemical test results show that corrosion resistance of the Ni-P coating after 200℃ heat treatment is better than that of the commonly used steels 20 R,ND and 316 L,with a higher self corrosion potential（-234 mV）,a smaller self corrosion current density（3.8687×10^-6 A·cm^-2） and a larger charge transfer resistance（954.9 Ω·cm^-2） in 5%sulfuric acid solution.Based on the results of uniform corrosion test in different concentration of sulfuric acid solution at 60℃,the annual corrosion rate of the four materials is ordered as 20RNDNi-P316L.

关 键 词：NI-P镀层 热处理 耐蚀性 腐蚀速率 

分 类 号：TG142.7[一般工业技术—材料科学与工程]