A Study of the Corrosion Properties of 150Mn20Al10 Austenite Low-density Steel in the Flowing Seawater

In response to the adverse effects of grain growth and other defects on the corrosion performance of austenite based low density steel during vacuum induction melting, the vacuum induction melting of austenite low-density steel 150Mn20Al10 (20% Mn, 10% Al and 1.5% C, mass fraction, the same below) was used as the research object. The induction melting ingot was remelted using electro-slag remelting, and the ingot before and after electro-slag remelting was forged. The seawater simulated corrosion tests were conducted on three types of samples, such as vacuum induction melting forged rod, vacuum induction melting forged plate, and electro-slag remelting forged plate by an orthogonal experimental scheme. The effects of seawater flow rate, corrosion time, pH, and production process on the seawater corrosion weight increase of steel 150Mn20Al10 were studied. Subsequently, the scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X ray photo-electron spectroscopy (XPS) were used to characterize and analyze the macroscopic and microscopic morphology, micro-structure, and corrosion products of austenite low-density steel 150Mn20Al10.The results indicate that the primary and secondary factors affecting the increase of corrosion weight of induction melting forged rod, induction melting forged plate, and electro-slag remelting forged plate are flow rate, time, pH and materials. Under the same flow rate conditions, there are many products such as Al₂O₃ and Fe₃O₄ on the surface of electro-slag remelting forged plate, resulting in better corrosion properties than induction melting forged rod and plate. Three types of samples mainly exhibit uniform corrosion, with a small amount of pitting corrosion occurring locally, and the corrosion rate of electro-slag remelting forged plate during the corrosion process of flowing seawater is lower than that of induction melting forged rod and forged plate, and the sensitivity to pitting corrosion is weaker than that of induction melting forged plate and forged rod.