Effect of Sn on the Pitting Corrosion Behavior of Ultra‐Purified 17% Cr Ferritic Stainless Steel

Abstract

The influence of Sn on pitting corrosion of ferritic stainless steels has been investigated by AC and DC electrochemical methods in 3.5 wt% NaCl and gravimetric tests in 6 wt% FeCl3 at 25 °C. 0.14 wt% Sn addition can improve pitting potential, while excessive addition (about 0.33 wt%) can deteriorate pitting corrosion resistance. Sn‐bearing steels have higher passive film resistance and faster growth rate of more compact passive film, in which the charge carrier density is reduced probably due to the presence of SnO2. Dissolved Sn2+ can inhibit elementary anodic reactions. Therefore, the content of Sn should be optimized within 0.1–0.23 wt% to obtain better corrosion resistance.

Microstructure and Mechanical Properties of Inertia‐Friction‐Welded Fe–Cr–Ni–Mo High‐Strength Steel

“…It should be pointed out that due to the high temperature at the WZ, the carbides are partially or completely dissolved into the austenite at the time of heating. In the subsequent cooling process, the austenite is directly transformed into martensite without carbide precipitation, and Cr and Ni can improve the corrosion resistance; [36,37] so the corrosion resistance at the WZ is improved, and it still shows a bright crystal surface after being corroded with nitric alcohol. The carbon content of the steel is 0.32 wt%, which belongs to the compositional region of hypoeutectoid steel.…”