【摘要】 采用“C/N+Mn代Ni”的合金设计方法,制备出了一种具有良好热加工性能的低镍双相不锈钢21Cr-DSS,并研究了固溶处理工艺对新钢种微观组织、强韧性及耐点蚀性能的影响。结果表明:21Cr-DSS在热轧过程中铁素体比奥氏体更容易发生动态软化。固溶温度比保温时间对21Cr-DSS中两相比例的影响更明显,且奥氏体晶粒尺寸稳定性优于铁素体。随固溶温度升高,21Cr-DSS的强韧性得到改善,但当温度超过1100℃后,强韧性下降。在1050℃固溶处理30 min时,21Cr-DSS具有最佳的综合性能,此时强塑积为58.9 GPa%,-40℃低温冲击功为84 J,在3.5%氯化钠溶液中的点蚀电位为0.43V。21Cr-DSS比常规LDX2101具有更优异的热加工性能和强韧性,且耐点蚀性能基本相当。与AISI 304奥氏体不锈钢相比,21Cr-DSS的强度和耐点蚀性能明显更优。更多还原

【Abstract】 A novel low-nickel duplex stainless steel of 21Cr-DSS with excellent hot workability was prepared by the alloying design of “C/N+Mn instead of Ni”, while the effects of solid solution treatment on its microstructure, strength-toughness and pitting corrosion resistance were studied. The results show that the ferrite of 21Cr-DSS during hot-rolling is more susceptible to dynamic softening than austenite. The effect of solid solution treatment temperature on the ferrite/austenite ratio in 21Cr-DSS is more obvious than that of holding time, and the stability of austenite grain size is better than that of ferrite. The strength and toughness of 21Cr-DSS are improved with the increase in solid solution temperature, but when the temperature exceeds 1100 ℃, its strength and toughness are decreased. The 21Cr-DSS solid solution treated at 1050 ℃ for 30 min have the excellent comprehensive properties, with the PSE(product of strength and plasticity),-40 ℃ impact energy and pitting potential in 3.5% sodium chloride solution having been measured to be about 58.9 GPa%, 84 J and 0.43 V,respectively. The 21Cr-DSS has the more excellent hot workability and strength-toughness than LDX2101, and the similar pitting corrosion resistance. Compared with AISI 304 austenitic stainless steel, the 21Cr-DSS has the higher strength and pitting corrosion resistance.更多还原