日新制钢汽车排气系统用耐热铁素体不锈钢的开发  

Development of heat-resistant ferritic stainless steels for exhaust lines at Nisshin Steel

作　　者：Manabu Oku 李鑫（译） 毕洪运（校） 

机构地区：[1]日新制钢株式会社,日本 [2]不详

出　　处：《世界钢铁》2011年第5期10-16,共7页World Iron & Steel

摘　　要：为了减轻空气污染和缓解全球变暖,各个国家均出台了尾气排放标准,且限制标准越来越严格。在此背景下,多种技术已被应用以满足相关要求,如提高燃油燃烧率、催化效率,降低排气管热容量等。而这一系列措施均会导致汽车尾气的最高温度上升。近些年,汽车排气系统零件主要用铁素体不锈钢制作,因为铁素体不锈钢的热膨胀系数小,耐循环氧化和耐高温疲劳性能均优于奥氏体不锈钢。介绍了日新制钢新研发的汽车排气系统用耐热不锈钢,以及该钢种的研发现状和发展趋势。Nb、Mo、Cu在700℃时的固溶强化和析出强化对提高铁素体不锈钢的高温强度非常有效,而添加Nb、Mo、W主要是在900℃时起到固溶强化作用。Cr,Si和Mn可降低铁素体不锈钢(含14%Cr)在大气中950℃保温200h的氧化程度。特别是添加0.8%及以上的Mn可有效提高氧化皮的附着力。事实证明,日新制钢开发的NSSHR-1(14Cr-1Mn-0.9Si-Nb)和NSSHR-2(10Cr-0.9Si-Nb-Ti)铁素体不锈钢与441和439不锈钢相比,具有更高的耐热性和成形性。Exhaust emission regulations of the automotive are enforced in each country to prevent air pollution and global warming, and the restriction standard tends to become severer. Various techniques such as the combustion improvement of gasoline, upgrades of the catalyst, and the thermal capacity decreases in the exhaust lines are adopted to suit the regulations, and these lead to an increase of the maximum temperature of the exhaust gas. Recently, ferritic stainless steels are mainly used to parts of exhaust lines, as their thermal expansion coefficient is small, and the cyclic oxidation resistance and the thermal fatigue property are better than austenitic stainless steels. This paper presents newly developed heat-resistant stainless steels from Nisshin Steel for exhaust lines usage, and describes the currents of the steel development that could be envisaged in the futurel With regard to improving the high-temperature strength of ferritic stainless steels, the addition of Nb, Mo and Cu is effective in solution hardening and precipitation hardening at 700℃, while the addition of Nb, Mo and W is effective in mainly solution hardening at 900℃. The addition of Cr, Si and Mn suppress the breakaway oxidation in air at 950℃ up to 200h of ferritic stainless steels containing 14% Cr. Especially, the addition of 0.8% or higher Mn would effectively improve the adherence of oxide scale. It is confirmed that ferritic stainless steels, NSSHR-1 （14Cr-lMn-0. 9Si-Nb） and NSSHR-2 （ 10Cr-0.9Si-Nb-Ti）, is having a superior heat resistance, formability and cost performance compared to conventional Type441 and Type439, respectively.

关 键 词：铁素体不锈钢 高温强度 热疲劳 抗氧化性能 氧化皮附着性 

分 类 号：TG142[一般工业技术—材料科学与工程]