09CUPCRNI-B weathering steel for high-strength containers has good resistance to atmospheric and seawater corrosion. The improvement of its corrosion resistance is mainly due to the combined action of Cu and P elements. Welcome to send email to
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However, in the 09CUPCRNI-B weathering steel during high temperature heating of the slab, because the matrix iron is easily oxidized selectively, the iron oxide will enrich a layer of liquid copper under the skin, this "copper-rich liquid phase" is along the austenite grain boundary It penetrates to the inside, and it is easy to cause cracks on the surface and edges of the slab during rolling.
Therefore, 09CUPCRNI-B weathering steel generally suppresses "copper-induced surface thermal cracking" by adding nickel. The amount of nickel added is related to the content of copper, and the nickel / copper ratio is generally required to be close to 1: 1. In recent years, with the in-depth study of copper-containing steel and the improvement of rolling technology at home and abroad, some patents and literatures have proposed to improve the rolling and heating process measures to suppress the surface thermal cracking of copper-containing steel after removing nickel. In order to make this kind of technology applied to the actual production of 09CUPCRNI-B weathering steel, the impact of nickel reduction on the seawater corrosion resistance of 09CUPCRNI-B weathering steel is urgently studied in the industry.
Effect of ingredients on 09CUPCRNI-B steel: The 0.25% Ni element in 09CUPCRNI-B weathering steel has a certain degree of influence on the corrosion resistance of the experimental steel. When the Ni content decreases from 0.25% to 0%, the corrosion resistance of the experimental steel is slightly reduce. Therefore, it is necessary to improve the corrosion resistance of newly developed low-cost nickel-free weathering steel through the joint adjustment of other alloying elements. Starting from the low-cost alloy elements Si, C, and S, this study designed a composition design route for increasing Si, reducing C, and reducing S. Among them, the reduction of C is to reduce the content of pearlite, and to reduce the area with weak corrosion resistance on the surface of the sample. At the same time, according to Chen Xuequn and other studies on the influence of sulfide inclusions on the pitting corrosion of low-carbon steel, a design scheme of reducing S is adopted. To reduce the content of sulfide inclusions that can be used as a source of pitting corrosion; in addition, Sei J Oh et al. experimental results on 09CUPCRNI-B weathering steel exposed to air show that higher Si content is beneficial to refine the rust layer structure and reduce the overall steel The corrosion rate, therefore, slightly increased the Si content. From the results of this experiment, it can be seen that the combined adjustment of the C, S, and Si elements has improved the corrosion resistance of the experimental steel, and the corrosion resistance of the newly developed 4 # nickel-free weathering steel has been significantly improved.
