论文部分内容阅读
在海水飞溅区对实验室冶炼的Ni-Cu-P钢、含Cu低合金钢和碳钢进行660 d的挂片实验,评价Ni-Cu-P钢的耐蚀性能;采用Fourier变换红外(FTIR)光谱、电感耦合等离子体原子发射光谱(ICP-AES)、电子探针(EPMA)、SEM和EDAX等技术,分析3种钢表面的锈层特征.结果表明,Ni Cu P钢表现出比碳钢优越的耐全面腐蚀和点蚀能力.对锈层成分分析发现,在宏观阴极区,钢的内、外锈层均主要由α-FeOOH,β-FeOOH,γ-FeOOH,δ-FeOOH,Fe_3O_4和少量非晶氧化物组成,但内锈层的Fe_3O_4含量更高,而γ-FeOOH和β-FeOOH的含量更低.与碳钢相比,Ni-Cu-P钢宏观阴极区和蚀坑内的锈层更致密.对锈层中的合金元素分析发现,Ni-Cu-P钢中的合金元素Ni,Cu和P主要分布在宏观阴极区的内锈层和蚀坑内,Cu和P在蚀坑内有富集.在宏观阴极区,合金元素Cu可细化内锈层的晶粒,从而促进保护性锈层的形成.在蚀坑内,Cu富集在锈层中的夹杂物周围,对锈层中的裂纹和孔洞起修复作用.合金元素Cu和Ni可提高蚀坑内基体的电位,P有助于降低钢蚀坑内基体的腐蚀速度,因此,Ni-Cu-P钢比碳钢表现出强的耐点蚀性能.
The corrosion resistance of Ni-Cu-P steel was evaluated on the coupons of Ni-Cu-P steel, Cu-containing low-alloy steel and carbon steel which were smelted in the laboratory for 660 days in seawater splashing area. Fourier transform infrared (FTIR ) Spectra, inductively coupled plasma atomic emission spectrometry (ICP-AES), electron probe (EPMA), SEM and EDAX were used to analyze the rust characteristics of the three kinds of steel. The corrosion resistance and pitting corrosion resistance of steel are superior to those of steel.The composition analysis of the rust layer shows that the internal and external rust layers of the steel are mainly composed of α-FeOOH, β-FeOOH, γ-FeOOH, δ-FeOOH, Fe_3O_4 And a small amount of amorphous oxide, but the content of Fe_3O_4 and γ-FeOOH and β-FeOOH in the inner rust layer is lower than that of the carbon steel.Compared with the carbon steel, the macro-cathode area of Ni-Cu-P steel and the The rust layer is denser.Analysis of alloying elements in the rust layer shows that the alloying elements Ni, Cu and P in the Ni-Cu-P steel are mainly distributed in the inner rust layer and pits in the macro-cathode region and Cu and P are in the pits There is enrichment in the macro cathode area, the alloying element Cu can refine the grain rust layer, thereby contributing to the formation of protective rust layer in the pit, Cu enrichment around the inclusions in the rust layer, the Cracks and holes in the rust layer play a repair role. Alloying elements Cu and Ni can improve the potential of the substrate in the pits, which helps to reduce the corrosion rate of the substrate in the pitting pits. Therefore, the Ni-Cu-P steel shows a higher corrosion resistance than the carbon steel Strong resistance to pitting performance.