Enhancing plasticity, wear and corrosion resistance of WAAM duplex stainless steel through solution treatment
摘要
The ratio of ferrite to austenite in duplex stainless steel significantly affects its mechanical properties. In order to regulate the proportion of ferrite and austenite in duplex stainless steel produced by arc additive manufacturing and improve the mechanical properties of duplex stainless steel, the deposited samples of TIG arc additive manufacturing were treated by solution treatment. The effects of solid solution temperatures of 1200 ℃, 1250 ℃, 1300 ℃, and 1350 ℃ on the microstructure and properties of deposited samples were studied and compared with untreated samples. The results showed that as the solution temperature increased from 1200 °C to 1350 °C, the proportion of α-ferrite in the sample and the hardness of the sample increased, and the elongation of the sample increased first and then decreased. At a solutionizing temperature of 1250 ℃, the two-phase ratio in the deposited sample was close to 1 : 1, and the plasticity, wear resistance and corrosion resistance of the deposited sample were the best. the elongation in the horizontal direction reached 36.9%. The corrosion current density, corrosion hole area and number of the sample were 1.44 µA/cm2, 8 µm2 and 32, respectively. The friction coefficient of the sample was 0.53, and the wear mass and wear volume were 0.7 mg and 2.12 mm3, respectively. By comparing the XRD results of the surface before and after wear, the oxides produced in the wear scar were mainly composed of Fe2O3, Mn3O4 and Cr2O3. The dry friction and wear mechanism of duplex stainless steel fabricated by arc additive manufacturing at room temperature involved adhesive wear, abrasive wear and oxidation.