预镀镍层对一种C-Mn-Si高强钢选择性氧化行为的影响

目的 抑制高强钢中合金元素在表面选择性氧化.方法 在一种C-Mn-Si体系高强钢表面预先电镀100 nm厚度的镍,然后在镀锌模拟器上进行模拟退火处理.使用扫描电镜及其附属的X射线能谱仪观察分析了试样表面形貌和元素构成,使用辉光放电光谱仪研究了样品退火后表面的元素深度分布,使用X射线光电子能谱鉴定了样品退火后的表面化合物...

Influence of Prior Nickel Plating on Selective Oxidation Behavior of a C-Mn-Si High Strength Steel

The study aims to suppress selective oxidation on the surface of an advanced high strength. A C-Mn-Si high- strength steel was electrodeposited with prior nickel plating with the thickness of 100 nm, and then annealed in a galvanizing simulator. The surface morphology and elemental composition of the samples were studied using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) attached, respectively. The element depth distribution in the surface layer of the samples was studied through a glow discharge spectrometer (GDS). X-ray photoelectron spectroscopy (XPS) was used to identify the category of the compounds on the external surface. The annealed sample with prior-nickel plating could be found to have a loose nickel layer on the surface and some oxides could be observed on the nickel layer. For the annealed sample without prior-nickel plating, oxides could be found in the boundaries and in the grains. With annealing time prolonging, more oxides appeared on the surface and less nickel content was detected. GDS results revealed that the nickel plating deposited on the surface could inhibit the selective oxidation of alloy elements on the external surface. As annealed for 10 s, enrichment of Mn on the surface was reduced by 52% and enrichment of Si on the surface was reduced by 23%. As annealed for 50 s, enrichment of Mn and Si on the surface were both reduced by 42%. X-ray photoelectron spectroscopy analysis showed that the oxides on the surface of the nickel-plated samples were mainly amorphous oxides, while a large amount of crystalline oxides appeared on the surface of the nickel-free samples. It was indicated that that prior nickel plating with 100 nm thickness can effectively decrease diffusion rate of Si and Mn, suppress the enrichment of Si and Mn on the external surface, change the type of surface selective oxidation products, and reduce the amount of surface oxides on high-strength steel.