针对高镍奥氏体铸铁成本高的特点,拟通过用价格低廉的锰代替价格昂贵的镍,并调整Cu,Cr和Si等元素含量,制备低镍奥氏体铸铁。研究镍铸铁在5%(质量分数)HCl溶液中的腐蚀行为和在3.5%(质量分数)NaCl溶液中的电化学腐蚀行为及在干摩擦条件下的耐磨损性能。研究结果表明:在5%HCl溶液中,低镍铸铁耐腐蚀性能与高镍铸铁的耐腐蚀性能相当;同时,所有镍铸铁试样在3.5%NaCl盐溶液中的电化学腐蚀行为都出现了氧扩散的平台,并且白腐蚀电流密度与自腐蚀电位随着Ni,cr和Cu含量的降低而不同程度地增加;在干摩擦条件下,低镍铸铁的耐磨损性能接近或高于高镍铸铁的耐磨损性能,其主要的磨损机制是黏着磨损,同时还存在疲劳磨损和磨粒磨损。
Based on the fact that application of the high-nickel austenitic cast iron results in high cost, the low-nickel austenitic cast iron was prepared by reducing the nickel content of the cast iron with substitution of Mn for Ni and simultaneously controlling the content of Cu, Cr and Si. The corrosion behavior of low-nickel austenitic cast iron was studied in 5%(mass fraction) HCI solution. At the same time, the electrochemical behavior in 3.5%(mass fraction) NaC1 solution and the wear resistance under dry friction condition were also investigated. The results show that the corrosion resistance of the low-nickel austenitic cast iron in 5% HC1 solution is very close to that of high-nickel austenitic cast iron. In the polarization curve of all nickel austenitic cast iron samples in 3.5%NaC1 solution, there emerges the platform of oxygen diffusion. With the decrease of the addition of Ni, Cr and Cu, the corrosion current density and the corrosion potential are increased to some extent. Under the conditions of the dry friction, the wear resistance of low-nickel cast iron is similar or a little higher than that of high-nickel cast iron. The adhesive wear is the main wear mechanism, and there exist fatigue wear and abrasive wear.