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表面沉淀硬化不锈钢的研究

Study on Surface Precipitation Hardening Stainless Steel

【作者】 刘小萍

【导师】 苏永安;

【作者基本信息】 太原理工大学 , 材料加工工程, 2001, 硕士

【摘要】 不锈钢是指铬含量大于10.5%的耐腐蚀合金钢。这类钢除含铬外,通过加入其它合金元素,如镍、钼、钛、铌等,形成系列不锈钢。不锈钢分为四类:奥氏体不锈钢、铁素体不锈钢、双相不锈钢、马氏体不锈钢及沉淀硬化不锈钢。其中,沉淀硬化不锈钢具有较优良的强韧性和耐蚀性。但其高昂的价格限制了这类钢在普通工业上的应用。 利用双层辉光离子渗金属技术研制出一种新型的表面沉淀硬化不锈钢。它是在普通材料表面形成含有合金元素铬、钼、镍、钴的合金层,通过固溶、冷处理及时效等热处理,使该合金层具有与冶炼沉淀硬化不锈钢相当的性能。 工艺试验结果表明:(1)利用重量百分比为Co55Cr25Ni5Mo15的粉末冶金板作为合金元素的供给源(源极),通过1050℃双辉渗金属,能够在纯铁表面形成重量百分比为Co24Cr13Ni4Mo4的合金层,其成分类似马氏体沉淀硬化不锈钢;(2)固溶状态该渗层硬度在230~300HV之间,易于机加工,500~560℃低温时效后,渗层硬度达500HV以上,具有较好的耐磨性。 与纯铁及不锈钢0Cr18Ni9性能对比试验结果表明:(1)表面沉淀硬化不锈钢在5%HCl溶液中的耐蚀性优于上述两种钢,在5%NaCl溶液中的耐蚀性与纯铁及不锈钢相当;(2)表面沉淀硬化不锈钢有较好的耐磨性。 表面沉淀硬化不锈钢与整体冶炼沉淀硬化不锈钢相比,不仅制造工艺简单,而且可节约大量合金元素,制造成本低。其优良的性能将会使这种太原理工大学硕士学位论文摘要新型的表面合金具有广泛的应用前景。

【Abstract】 Stainless steel is a generic term for a family of corrosion resistant alloy steels containing 10. 5% or more chromium. In addition to chromium, nickel, molybdenum, titanium, niobium and other elements may also be added to stainless steels in varying quantities to produce a range of stainless steel grades. In comparison with other four kinds of stainless steels (austenitic, ferritic, duplex and martensitic), the precipitation hardening stainless steel (PHSS) combines highest strength and hardness with good corrosion resistance, and is suitable for easy fabrication, but the use of PHSS is limited because of its more expensive cost.A kind of new surface precipitation hardening stainless steel (SPHSS) , which has a similar property with PHSS is developed on the surface of iron or plain steel by use of Double Glow Surface Technology. The SPHSS is composed of base materials (iron or plain steel) and the surface alloyed layer based on them, containing the alloy elements of Cr, Mo, Ni and Co. The process of SPHSS, consisted of double glow plasma surface alloying (Xu-Tec Process), solution treatment, cold treatment and aging, is introduced in this paper.Experimental results show that: (1) using power metallurgy alloy Co55Cr25Ni5Mol5 as source material, the composition of the top alloyedlayer on the surface of iron is about Co24Crl3Ni4Mo4, similar with the composition of Martensitic PHSS; (2) supplied in a solution treated condition, the structure of alloyed layer is composed of plate martensitic with hardness of 230-300HV (in which it is machinable) and can be hardened in a single low temperature ageing process (450-600HV) ; (3) SPHSS is moderated to better wear resistance and excellent corrosion resistance in 5%HCL solution than pure iron and OCrl8Ni9, and its corrosion resistance in 5%NaCl solution is comparable to grade of OCrl8Ni9 and pure iron.The extraordinary and unique properties of SPHSS, especially its lower price, will make these exceptional alloy materials of construction in many industries in the future.

  • 【分类号】TG174.4
  • 【被引频次】2
  • 【下载频次】297
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