Effect Of Composition Modification On Corrosion Resistance Of Container Steel In Marine Atmosphere

In recent years, weathering steels are wildly used in the manufacture of container steels owing to their excellent corrosion resistance. The application of weathering steels not only extending the service life of the container steels, but also playing a positive role in promoting the development of ocean shipping industry. We must add Ni, Cr, Cu alloy elements to improve the corrosion resistance, but, some alloy elements are uncommon and expensive. They also increase the production cost, then affect our country's state-owned market share. This paper aims to reduce the alloy element cost of SPA-H container steels, mainly research the corrosion behavior and corrosion mechanism of the three weathering steels with different alloy elements in marine atmosphere, and the corrosion resistance of the hot rolling oxide skin on the surface of weathering steels. The main conclusions are as follows:(1)In the condition that Cu and Ni contents are low, improving the content of Cr lonely has bad effect on the corrosion resistance of weathering steels; If the content of Cr is invariant, reducing the contents of Cu and Ni has disadvantageous effect in the late corrosion time. It can not improve the corrosion resistance at root.(2) Banded structure plays a leading role in the early time of corrosion resistance, witch caused by alloy elements.(3) The result of indoor cycle infiltrating corrosion experiment matches the domestic prediction model D = Atn, and this model can be used to test the corrosion resistance decreases performance for preliminary forecast.(4) According to the speed-up radio by indoor experiment and atmospheric exposure experiment, The test weathering steel witch reduce Ni can meet the operating requirement.(5)The existence of hot rolling oxide skin has no influence on the corrosion mechanism, it just improves the steel basic stability, and plays the role of physical barriers.