共查询到19条相似文献,搜索用时 171 毫秒
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本文介绍了不同成分的Mn、Cu、Sn新型低合金耐磨耐蚀铸铁。经研究表明,Mn使Cu在铸铁中的固溶度增加,在Cu含量达到固溶度之前,Cu对硬度的贡献较大。是一种适合于耐蚀又耐磨条件下应用的新型低合金耐磨耐蚀铸铁。 相似文献
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阐述了铸铁的腐蚀机理及特点,分析了铸铁与铸钢阀门在海水中的腐蚀速度,介绍了孕育铸铁加合金后抗腐蚀能力及镍铬铸铁工况运行情况。 相似文献
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铸铁中的化学成分对热导率的影响 总被引:2,自引:0,他引:2
本文讨论了一些化学元素对铸铁热导率的影响,认为低合化对铸铁热导率影响较小,可用低合金化来改善受热铸铁件的高温力学性能和抗氧化性,而又不过多损害热导性。 相似文献
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分别对未变质和经稀土变质处理的低合金耐磨铸铁进行了热疲劳循环试验,研究了稀土变质处理对低合金耐磨铸铁热疲劳性能的影响.结果表明:该耐磨铸铁经稀土变质处理后,其共晶碳化物由未变质的网状分布变成断续网状和孤立块状分布,热疲劳裂纹扩展激活能由变质前的26.52 kJ·mol-1增大到变质后的30.15 kJ·mol-1,热疲劳裂纹扩展速度降低,变质处理提高了该耐磨铸铁的热疲劳性能. 相似文献
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锻造白口铸铁轧辊使用的是高碳低合金材料DT21,其可塑性低且可焊性差。为减少废品损失,一重集团公司在引进山东工业大学的白口铸铁冷补焊专利技术的同时,继续进行了大量工艺性试验。本文论述了冷补焊、予热补焊及冷热结合补焊3种工艺的模拟试验,并对试验结果进行了理论分析。实践表明,对于低塑性材料轧辊的小缺陷,冷补焊工艺可行;而对于较大缺陷,则宜采用冷热结合的补焊工艺。 相似文献
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低合金冷硬铸铁凸轮轴具有优异的抗磨性,且加工余量小、成本低廉,被广泛地应用于内燃机生产。乐亭县汽车零件厂自1985年以来,为北京内燃机总厂配套生产475Q型冷硬铸铁凸轮轴,该轴经北内在发动机试验台上做250h的负荷疲劳磨损试验,凸轮磨损量仅为0.02~0.03mm,其余指标与日本进口的 相似文献
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本文讨论了一些化学元素对铸铁热导率的影响,认为低合化对铸铁热导率影响较小,可用低合金化来改善受热铸铁件的高温力学性能和抗氧化性,而又不过多损害热导性。 相似文献
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本文介绍了根据轧辊摩擦系统选择高抗磨材料高铬铸铁,采用分段镶套法修复冷硬铸铁轧辊的工艺。在实验的基础上分析了高铬铸铁的耐磨特性和耐磨铸套的生产工艺特点,提供了一种轧辊修复再生方案,解决了普通冷硬铸铁轧辊耐磨性差,使用寿命短,设备维修费用高的问题。 相似文献
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介绍了低镍铬合金铸铁+重防腐涂料在核电站耐海水阀门领域的使用情况。基于台山核电项目CRF系统蝶阀主体材料采用低镍铬合金铸铁,对比分析了低镍铬合金铸铁+重防腐涂料、碳钢衬胶、双相不锈钢及铜合金等常用耐海水腐蚀性材料在使用性、工艺性和成本等方面的差异。 相似文献
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Corrosion and wear resistance characteristics of NiCr coating by laser alloying with powder feeding on grey iron liner 总被引:6,自引:0,他引:6
To reduce the mixed fuel induced excessive wear of the cast iron engine cylinder liners, research on laser alloying of NiCr alloy with powder feeding was performed to locally change both the composition and the microstructure of the liner. The research indicated that laser alloying of 75Ni25Cr on grey cast iron liner demonstrates sound alloying layers free of cracks and porosities. The microstructure of the alloyed layer is composed of pre-eutectic austenite and ledeburite. The alloying element Ni is mainly located in the austenite, while Cr is mainly in cementite. The average hardness is HV0.2500. The corrosion resistance of the alloyed layers in diluted H2SO4 solution and NaOH solution is dramatically improved compared to the grey cast iron. The relative wear resistance of the laser-alloyed 75Ni25Cr layer is 4.34 times of that of the grey cast iron. The improvements on the corrosion and wear resistance of the cast iron are attributed to the composition and microstructure change by laser alloying of 75Ni25Cr. Laser alloying can be a good solution to improve wear and corrosion resistance of the grey iron liners in mixed fuel environment. 相似文献
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为了深入了解冷激合金铸铁气门挺杆的磨损规律,研究了冷激合金铸铁气门挺杆表层组织对耐磨性的影响.结果表明:当气门挺杆组织中的石墨以点状均匀分布,碳化物呈细小针状、块状,分布较为均匀时,耐磨性较好,磨损形式以划伤、点蚀为主;当气门挺杆组织中的石墨以片状均匀分布,碳化物呈粗大针状、块状,分布不均匀时,耐磨性较差,磨损形式以剥落为主. 相似文献
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RESEARCHANDAPPLICATIONOFASCASTWEARRESISTANCEHIGHCHROMIUMCASTIRONLiuJinhaiLiuGenshengLiGuoluHebeiUniversityofTechnologyWangKu... 相似文献
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在分析MPS(MBF)型中速磨煤机用磨辊的工况条件和性能要求的基础上,结合国内资源,设计确定了材料的成分组成,制定了合理的铸造、热处理工艺,成功地研制了适合我国煤质特点的高铬白口铸铁磨辊.试验运行结果表明,同样工况条件下,所研制的高铬白口铸铁磨辊的耐磨寿命比进口镍硬N#铸铁提高50%以上,且成本降低,经济效益十分可观. 相似文献
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A study of sand slurry erosion of W-alloy white cast irons 总被引:1,自引:0,他引:1
This paper reports the results of a study into the effects of the composition, hardness and electrochemical properties of W-group cast irons on sand slurry-erosion resistance and wear mechanisms. The results indicate that the sand slurry-erosion resistance of the irons can be raised by increasing the content of tungsten, especially when the iron is alloyed with chromium. The relation between macrohardness and sand slurry-erosion is intricate. In the low hardness range, the sand slurry-erosion resistance is linearly increased with hardness, but this relationship does not exist in the high hardness range. The sand slurry-erosion resistance of cast iron can be considerably increased by increasing its corrosion resistance. Sand slurry-erosion is an abrasive wear process accompanied by corrosion and cavitation, all of which aggravate each other. 相似文献
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In many slurry transportation systems, such as in FGD (Flue Gas Desulphurization) and chemical processing applications, corrosion and erosion are the two main mechanisms of material degradation of the pump wet-end components including pump casing, impeller and liners. The performance of a selected material is mostly dependent upon its relative corrosion and erosion resistance to the service environment. In these cases erosion, corrosion and the related synergistic effects can be very complicated since they are affected by numerous factors including solid and slurry properties, chemical contents, hydraulic conditions and temperatures. In this experimental study, sliding Coriolis erosion testing has been performed with various corrosion factors such as pH value, chlorides content and temperature to evaluate the erosion–corrosion resistance of some high-alloyed white cast irons containing different levels of chromium and other elements. Optical microscope and SEM-EDS have also been used to examine microstructure and surface conditions of tested materials. Results indicated that material loss due to corrosion factors increased as acidity-chlorides and temperature increased. At relatively high corrosion intensity, the white cast irons with higher alloy content (especially chromium) clearly showed improved corrosion resistance and combined erosion–corrosion resistance over those with lower alloy content. Under certain corrosion and hydraulic conditions, particle size is perhaps the single most influential factor on erosion–corrosion rate of the high-Cr cast iron alloys. Relatively large particles are much more effective than small ones at removing both the corroded surface layer and the fresh material, causing substantially higher rate of material loss. Some other related factors have also been addressed. 相似文献