TWIP钢表面Ni-P化学镀层组织结构及性能研究  

Investigation on Microstructure and Corrosion Resistance of Electroless Ni-P Coating on TWIP Steel

作　　者：岳丽杰[1] 薛广成 谢鲲[1] 韩金生 孙一品 YUE Lijie;XUE Guangcheng;XIE Kun;HAN Jinsheng;SUN Yipin(School of Material Science and Engineering,Shandong University of Science and Technology,Shandong Qingdao 266590,China;School of Civil Engineering and Architecture,Shandong University of Science and Technology,Shandong Qingdao 266590,China)

机构地区：[1]山东科技大学材料科学与工程学院,山东青岛266590 [2]山东科技大学土木工程与建筑学院,山东青岛266590

出　　处：《表面技术》2024年第16期89-102,共14页Surface Technology

基　　金：国家自然科学基金(51208288)。

摘　　要：目的在孪生诱发塑性钢(TWIP)表面制备Ni-P镀层,提高TWIP钢的耐腐蚀性能。方法通过化学镀工艺在TWIP钢表面制备了高磷Ni-P镀层,并进行不同温度的热处理,利用扫描电镜及能谱仪、X射线衍射仪及原子力显微镜等探究了热处理温度和时间对Ni-P镀层形貌和组织结构的影响。通过电化学方法研究了TWIP钢表面镀层的耐蚀性能。结果随着热处理温度的升高,镍磷原子发生迁移,胞状组织边界模糊,粗糙度降低,其中600℃热处理镀层表面最为致密平整。随着热处理温度的升高,镀层组织结构演变过程如下:非晶态(普通镀层)→非晶态部分晶化,Ni12P5、Ni5P2等亚稳态镍磷化合物析出(300℃)→非晶态完全晶化、稳态Ni3P相长大(400℃)→晶粒长大(500℃、600℃)。Ni-P镀层能够明显提升TWIP钢的耐腐蚀性能。随着热处理温度的升高,镀层的耐蚀性能先降低后升高。600℃热处理1h镀层的腐蚀电流密度为0.25μA/cm^(2),与普通Ni-P镀层相比降低了80.9%,与TWIP钢基体相比降低了99.6%。600℃热处理镀层光滑致密无缺陷的表面促进了保护性氧化膜的产生,使镀层的耐蚀性能提高。结论合适的热处理工艺提高了Ni-P镀层的致密性和保护能力,光滑致密无缺陷的镀层能够为TWIP钢提供良好的防护。As advanced high-strength steel,twinning-induced plasticity(TWIP)steel has the high product of strength and plasticity,excellent impact resistance and good weldability.However,TWIP steel has poor corrosion resistance due to the presence of active Mn elements with high content,especially in the non-oxidizing acid solutions or environments containing chloride.In this paper,in order to improve the corrosion resistance of TWIP steel,high-phosphorus Ni-P binary coatings were prepared on the Fe-Mn-Al-C TWIP steel.Prior to the electroless plating test,samples with dimensions of 10 mm×10 mm×3 mm were mechanically ground with sandpaper,then polished with a 1μm diamond paste,followed by ultrasonic cleaning using ethanol and acetone.The pre-treatment process before plating mainly included alkali washing,acid pickling and activation.The Ni-P coatings on the TWIP steel samples were electrolessly deposited in an acidic hypophosphite-reduced nickel bath at 90℃,and a pH of 4.7 for 2 h plating duration.In the electroless plating bath,nickel sulphate(NiSO_(4)·6H_(2)O)was used as the source of nickel,sodium hypophosphite(NaH_(2)PO_(2)·H_(2)O)as the reducing agent and P source,lactic acid(CH3CHOHCOOH)and acetic acid(CH3COOH)as the complexing agents,and a little amount of thiourea as the stabilizing agent.The depositions were annealed in a tube furnace under high purity argon inert atmosphere at 300,400,500,600℃for 1,2,4 h,respectively.The effect of heat treatment temperature and time on the microstructure evolution and morphologies of electroless Ni-P coatings was analyzed by scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),electron probe microanalyzer(EPMA)and X-ray diffractometer(XRD).The surface roughness of the coatings after annealing treatment was measured by means of atomic force microscope(AFM).The corrosion resistance of Ni-P coatings on the surface of TWIP steel was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy(EIS)tests.The results showed that compare

关 键 词：TWIP钢 NI-P镀层 表面处理 热处理 耐蚀性能 

分 类 号：TG174.2[金属学及工艺—金属表面处理]