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用等离子氮弧冶炼不同氮含量的铬锰不锈钢,其耐腐蚀性能用动电位扫描、电化学阻抗等方法测试,并与1Cr18Ni9不锈钢作比较,结合显微组织分析耐蚀原因。实验结果表明含氮钢的耐蚀性普遍好于1Cr18Ni9不锈钢。随钢中含氮量增加,奥氏体组织扩大,耐腐蚀性能提高。当含氮量达0.74%时形成完全的奥氏体相。经阳极极化后,含氮钢表面的腐蚀层中奥氏体相比原基体的扩大,膜致密,耐腐蚀性能远远高于原基体。 相似文献
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医用不锈钢的研究与发展 总被引:1,自引:0,他引:1
不锈钢由于具有优异的力学性能、耐蚀性能和加工性能而被广泛应用于各种医疗器械及手术工具的制造。概述了医用不锈钢的特点和临床应用,以及存在的主要问题,并以高氮无镍奥氏体不锈钢、不锈钢表面改性、抗菌不锈钢为重点,介绍了医用不锈钢近年来在国内外的主要研究进展。表明医用不锈钢的研究与发展,进一步提高或改善了不锈钢的生物安全性、力学性能、耐蚀性能,甚至带来了一些生物功能化,为医用不锈钢的临床应用带来了新的机遇。 相似文献
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Austenitic chromium–manganese–nitrogen stabilized stainless steels have been developed to replace chromium–nickel–nitrogen stainless steels in certain applications. In comparison, chromium–manganese–nitrogen steels have improved mechanical properties and acceptable corrosion resistance in hot, high chloride containing media. In this paper, corrosion fatigue investigations of a solution annealed and for practice more relevant 14% cold worked high alloyed chromium–manganese–nitrogen steel have been done. Inert glycerine was used as reference media and 62% calcium chloride solution as corrosive media, both aerated at a temperature of 120 °C. The stress ratio between upper and lower stress levels was 0.05 (tension–tension loading) to avoid the destruction of the fracture surfaces. As testing frequency for the dynamic experiments, 20 Hz was chosen considering possible application areas. Maximum stress versus number of cycles curves were recorded and representative specimens were investigated in a scanning electron microscope. In addition, electrochemical tests, exposure tests and constant load tests were done. This paper shows results on the corrosion fatigue of a manganese–nitrogen stabilized austenitic steel in a hot high chloride containing salt solution and helps to get a better understanding of occurring failure mechanisms. 相似文献
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Highly corrosion resistant special steels for flue gas desulfurisation plants Highly corrosion resistant stainless steel grades have been proved under the severe corrosion conditions existing in flue gas desulfurisation scrubbers (FGD). Besides general corrosion pitting, crevice corrosion and eventually stress corrosion cracking can occur. Thus highly alloyed special steels must be used. Steel grades with a minimum content of 2.75% Mo are essential. At higher chloride levels and decreasing pH-values higher alloyed stainless steels containing up to 6% Mo are necessary. Some of these special steels are described in view to their composition and mechanical properties; their corrosion behavior has been tested under laboratory and field conditions. The use of nitrogen alloyed grades has been shown of remarkable advantage. Nitrogen additions enhance the mechanical properties and structure stability. Furthermore the precipitation of deleterious intermetallic compounds during heat treatment will be delayed by nitrogen additions, thus e.g. multi layer weldings can be carried out with higher security in view to corrosion resistance and mechanical properties. Materials selection for the different scrubber systems will be illustrated by examples. Up to now experiences about stainless steel components in FGD plants are taken into consideration. Welding with distinctly higher alloyed filler metal at the medium-touched side has been well proved in view to adequate corrosion properties. 相似文献
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不锈钢钢种发展的一些动向 总被引:4,自引:0,他引:4
从奥氏体不锈钢的演变,以氮代碳的含氮不锈钢,Mn-N系不锈钢,超级铁素体不锈钢,超级奥氏体不锈钢,超级马氏体不锈钢及抗菌不锈钢等方面的发展,概述了不锈钢钢种发展的一些动向。 相似文献
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HansBerns BerndEdenhofer RolandZaugg 《材料热处理学报》2004,25(5):354-359
SolNit^R is a novel heat treatment to case harden stainless steels with nitrogen instead of carbon. The calculated equilibrium pressure of N2 corresponds well with the nitrogen content in the steel surface. The process is carried out in vacuum furnaces with pressurized gas quenching. Numerous parts of different stainless steels have been successfully SolNit^R treated in industry leading to superior properties in respect to hardness/strength and corrosion resistance 相似文献
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镍含量对13Cr型低碳马氏体不锈钢性能的影响 总被引:5,自引:0,他引:5
镍是影响13Cr型低碳马氏体不锈钢性能的主要元素之一。本文研究了13Cr型不同镍含量的低碳马氏体不锈钢的力学性能,电磁性能,组织状态以及电化学条件下腐蚀电位变化等。研究确定:低碳马氏体不锈钢中镍含量在.5%-6.0%时,可获得良好的强韧性。作为软磁不锈钢使用,其镍含量控制在3.5%-4.5%区间内,可获得满意的综合力学性能和良好的电磁性能。 相似文献
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Corrosion behaviour of three austenitic Lotus-type porous high nitrogen Ni-free stainless steels exposed to an acidic chloride solution has been investigated by electrochemical tests and weight loss measurements. Polarization resistance indicates that the corrosion rate of Lotus-type porous high nitrogen Ni-free stainless steels is an order of magnitude lower than that of Lotus-type porous 316L stainless steel in acidic environment. The localised corrosion resistance of the investigated high nitrogen Ni-free stainless steels, measured as pitting potential, Eb, also resulted to be higher than that of type 316L stainless steel. The influences of porous structure, surface finish and nitrogen addition on the corrosion behaviour were discussed. 相似文献
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双相不锈钢兼具优异的力学性能、耐腐蚀性以及抗辐照能力,是核电站一回路主管道的关键结构材料。然而,在服役环境下长期工作,双相不锈钢中铁素体会发生调幅分解,生成富Fe的α相和富Cr的α′相,即产生热老化脆化现象,从而恶化合金的力学性能。本文综述了双相不锈钢的热老化机制,探索不同因素对合金相分解的影响,进而分析其微观组织及动力学演化规律。此外,利用计算机模拟平台对合金的相分解过程进行预测,可以缩短材料的研发周期和降低成本,对迫切解决双相不锈钢的热老化问题具有重要帮助。 相似文献
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Effect of nitrogen level in strain hardened stainless steel (SS) on crack growth rate (CGR) in simulated boiling water reactor conditions has been the focus of this study. Type 304 LN stainless steel has been used in a warm rolled condition containing two different levels of nitrogen. Clear intergranular (IG) fracture was observed in both the stainless steels. The CGR increased 3 times in the stainless steel with higher level of nitrogen at all levels of dissolved oxygen and this was related to the increase in yield strength due to rolling and dynamic strain aging (DSA). 相似文献
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Nitrogen alloyed in austenitic stainless steels improves austenite stability, mechanical properties and corrosion resistance. Steels supersaturated with nitrogen (“super-nitrogen steels”) have been investigated, which rival the latest ferritic steels in strength but have potentially greater toughness. 相似文献
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A. Chandrasekar J. Anburaj R. Narayanan V. Balusamy S. S. Mohamed Nazirudeen 《Journal of Materials Engineering and Performance》2013,22(4):964-973
The amount of nitrogen contained in super austenitic stainless steels (SASS) influences their properties significantly. The effect of maximum amount of nitrogen in the highly alloyed Cr and Ni SASS containing further additions of Mo and Mn is studied. The calculated nitrogen contents of the experimental alloys are compared with the actual nitrogen contents obtained in the alloys produced using induction melting furnace. The actual nitrogen content of the alloys is always lower than the calculated value, and this discrepancy is due to the presence of positive interaction parameters of Ni, Cu, and Si in the alloy. However, the yield of nitrogen in the liquid SASS is improved significantly with additions of Mn and Mo contents. The construction of multicomponent phase diagrams for SASS is demonstrated using Thermo-Calc software. SASS containing more nitrogen exhibited a very high strength without loss of toughness. 相似文献
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Sung-Ik Shim Yong-Soo Park Soon-Tae Kim Chi-Bok Song 《Metals and Materials International》2002,8(3):301-307
Austenitic stainless steels such as AISI 316L have been used in equipment in which fluid flows at high speeds which can induce cavitation erosion on metallic surfaces due to the collapse of cavities, where the collapse is caused by the sudden change of local pressure within the liquid. Usually AISI 316L is susceptible to cavitation erosion. This research focuses on developing a better material to replace the AISI 316L used in equipment with high speed fluid flow, such as impellers. The effects of Rare Earth Metal (REM) additions on the cavitation erosion-corrosion resistance of duplex stainless steels were studied using metallographic examination, the potentiodynamic anodic polarization test, the tensile test, the X-ray diffraction test and the ultrasonic cavitation erosion test. The experimental alloys were found to have superior mechanical properties due to interstitial solid solution strengthening, by adding high nitrogen (0.4%), as well as by the refinement of phases and grains induced by fine REM oxides and oxy-sulfides. Corrosion resistance decreases in a gentle gradient as the REM content increases. However, REM containing alloys show superior corrosion resistance compared with that of other commercial alloys (SAF 2507, AISI 316L). Owing to their excellent mechanical properties and corrosion resistance, the alloys containing REM have high cavitation erosion-corrosion resistance. 相似文献
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Properties of the newly developed steel X 2 CrNiMnMoN 23 17 6 4 A well balanced alloying composition allows to produce the high alloyed stainless steel X 2 CrNiMnMoN 23 17 6 4 containing more than 0.4% nitrogen by conventional processes. Features of this material are a stable fully austenitic microstructure, 0.2% yield strength higher than 420 N/mm2, excellent corrosion resistance and good working and welding properties. The critical pitting temperature evaluated in ferric chloride solution according to ASTM G 48–76 standard is higher than 85 deg C and it is only lightly lowered when tested in the as welded condition. By these properties Remanit 4565 S may bridge the gap between high-alloyed stainless steels and non-ferrous materials for applications in the chemical process industries. 相似文献
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Manuele Dabalà Irene Calliari Alessandra Variola 《Journal of Materials Engineering and Performance》2004,13(2):237-240
Super duplex stainless steels (SDSS) have been widely used as structural materials for chemical plants (especially in those
engaged in phosphoric acid production), in the hydrometallurgy industries, and as materials for offshore applications due
to their excellent corrosion resistance in chloride environments, compared with other commercial types of ferritic stainless
steels. These alloys also possess superior weldability and better mechanical properties than austenitic stainless steels.
However, due to their two-phase structure, the nature of which is very dependent on their composition and thermal history,
the behavior of SDSS regarding localized corrosion appears difficult to predict, especially in chloride environments. To improve
their final properties, the effect of the partition of the alloying elements between the two phases, and the composition and
microstructure of each phase are the key to understanding the localized corrosion phenomena of SDSS. This paper concerns the
effects of the SDSS microstructure and heat treatment on the SDSS corrosion resistance in aqueous solutions, containing different
amounts of NaCl at room temperature. 相似文献