Effects of La2O3 on Mechanical Properties and Corrosion Resistance of H62 Brass

In this article, the effects of lanthanum oxide (La2O3) on the microstructure and mechanical properties of H62 brass were investigated by using the universal testing machine, Brinell hardness tester, optical microscope, and scanning electron microscope (SEM). Immersion corrosion and electrochemical measurements were carried out to identify the influence of La2O3 on the corrosion behavior of the H62 brass. The phase constitution, microstructure, and phase composition of the H62 brass were analyzed by x-ray diffraction, SEM, and energy-dispersive spectrometer, respectively. The results show that the microstructure of α phase changes from dendrite grains to equiaxed grains, and the content and distribution of β phase are improved significantly. When the La2O3 content reaches 0.8 wt.%, the H62 brass obtains favorable comprehensive mechanical properties and the strength and hardness decrease but elongation increases, which is conducive to plastic processing. In addition, under the optimum amount of 0.8 wt.% La2O3 content, the corrosion rate of immersion corrosion attains the minimum values: As 12.6 g m−2 h−1, it decreases by 24%; as the corrosion potential changes from −1.1327 V to −0.328 V, it increases by 70.9%; and as the corrosion current density decreases from −2.833 mA mm−2 to −3.28 mA mm−2 corrosion, it decreases by 15.78%, when compared with H62 brass.