共查询到20条相似文献,搜索用时 15 毫秒
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KatsumiIchitani 《材料热处理学报》2004,25(5):453-456
Heat transfer coefficients of the quench medium are necessary for heat-treatment simulation. Cooling characteristics of quenching oil vary with kinds and usage greatly. Users are selecting oil solutions that come up to their desired hardness and quenching distortion requirements. In particular cooling performance rises by agitation and decompression. Therefore we identified a heat transfer coefficient by usage and kinds of quenching oil. Cooling characteristics are different greatly by a kind of quenching oil. A difference of a cooling characteristic by a kind of oil depends on a temperature range of a boiling stage and the maximum heat transfer coefficient mainly. On the other hand, in a convection stage, there are few changes in a boiling stage. Even if quenching oil temperature is changed, heat transfer coefficients do not change greatly. When quenching oil stirred, heat transfer coefficients of vapor blanket stage and a convection stage rise, but there are a few changes in a boiling stage. When quenching oil is decompressed a temperature range of a high heat transfer coefficient moves to the low temperature side. In addition, a heat transfer coefficient in a vapor blanket stage comes down. For precision improvement of heat-treatment simulation, it is important that the heat transfer coefficient is calculated in conformity to the on-site use reality. 相似文献
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通过研究石油钻井平台用A148GRADE105-85铸件的热处理工艺,确定了电机座、电机盖的调质热处理工艺。采用910℃水淬1.5 min后转油冷+610℃回火的工艺方法,可以生产出力学性能符合要求的电机座、电机盖。 相似文献
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论述了按照JB/T7951-2004《测定工业淬火油冷却性能的镍合金实验方法》和SH/T0220-92《热处理油冷却性能测试方法》测定淬火油和水溶性淬火剂的冷却性能的方法,其中包括测试中的一些关键点,例如探头的标定、打磨、清洗和电磁干扰的影响,热电偶的线性补偿,淬火油冷却性能的评定,以及注意事项等。 相似文献
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Lauralice de C. F. Canale Mauro R. Femandes Sylvana C. M. Agustinho George E. Totten Alessandro F. Farah 《金属热处理》2005,30(8):66-81
传统上,矿物油是常用淬火剂中最重要的一类淬火剂。然而,它们在本质上缺乏环保性,又有毒性,再从长期低价供应角度考虑,有必要寻找新的替代介质。石油制品油的淬火特性与其成分很有关系,因而受其氧化降解性能的限制。由于不断暴露在钢与油接触面问相对较高的温度中,石油制品油遭受热降解和氧化降解,使得其淬火特性发生明显变化。因此,淬火特性是任何一种可选择的淬火介质都必须要检验的一个非常重要的性能参数。可供选择的一类液态物质为植物油,它们具有典型的生物降解特性并且无毒。然而,植物油具有相对较差的抗氧化稳定性能,因此测定氧化对其淬火特性的潜在影响具有重要意义。本文报导的结果仅是这项巨大研究中的第一步,在这项工作中,对不受禁止的植物油的试验是在实验室设备上进行的,以前报告的促使石油制品油早期氧化的过程接近实际使用条件。依照ASTM D 6200标准,使用粘度计、红外线分光镜、^13CMR分光镜以及冷却曲线特性测定方法对所研究的液态植物油进行了性能检测并和典型的石油制品油作了成分比较。所得的结果表明,作为淬火介质,植物油是有前景的石油制品油的替代品,但在商业上要可行,同时必须使用适当的抗氧化剂。 相似文献
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张富群 《热处理技术与装备》2021,(1)
本文详细介绍了锻造冷作模具钢Cr12、Cr12Mo、Cr12MoV和Cr12Mo1V1的性能、热处理工艺和用途。并指出Cr12MoV钢最适合用于制造轧制焊接钢管模具,具有使用寿命长、性价比高的优点。重点论述了金润宝ZFQ-A型和ZFQ-BI类油聚合物水基淬火介质和ZFQ-BIIPAG聚合物水基淬火介质的冷却特性,三种水溶性淬火介质的最大冷却速度为15~151℃/s,300℃冷却速度为6.4~47.4℃/s。基本上满足各种高碳高铬铸铁(以Cr26为代表、中碳中合金钢和高碳高合金钢零件淬火工艺)的需要。其中15%浓度ZFQ-BI型类油聚合物水基淬火介质,成功地代替了淬火油,用于Cr12MoV焊接钢管轧辊的淬火。BI型类油聚合物15%水溶液与普通淬火油的冷却特性十分接近,最大冷却速度分别为64.2℃/s和83.5℃/s,300℃冷却速度分别为5.9℃/s和6.5℃/s。在马氏体转变阶段,产生的应力非常小,工件不发生开裂。 相似文献
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G. E. Totten H. M. Tensi K. Lainer 《Journal of Materials Engineering and Performance》1999,8(4):409-416
Immersion quenching is the most widely used quenching technique today and is usually one of the last steps in heat treat processing.
Improper hardening to incorrect cooling is generally a great loss and causes a great percentage of manufacturing costs. To
avoid a failure in cooling, researchers are committed to describing the cooling effect as precisely as possible.
The cooling of immersion cooled workpieces or probes is generally characterized by the process of wetting. Evaporable fluids
exhibit the three well known stages of cooling: vapor blanket stage, boiling stage, and convective heat transfer. Therefore
cooling behavior is influenced by a wide variety and depends on a number of parameters, that is, type of quenchant used, bath
temperature, rate of agitation, and the physical and chemical properties of the quenched parts.
Environmental pollution has caused the search for new products in har dening and shock cooling of steels. The use of soybean
oils as quenching fluids is new, and compared with standard mineral oils, there are many advantages mainly concerning the
environment and the health of workers. 相似文献
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AbstractModern quenching oils offer a wide range of capability and performance. The selection of the proper quench oil is critical for proper heat treating operations. Improper selection of quench oil can result in short oil life, or soft parts. This paper will illustrate the selection factors in choosing a quench oil to ensure proper quality parts. 相似文献
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以0Cr17Ni4Cu4Nb不锈钢底座为研究对象,通过工艺试验方法获得了既满足力学性能要求又满足畸变量控制要求的真空固溶时效工艺。结果表明,采用1060 ℃×1.5 h固溶,油冷+460 ℃×4 h时效,空冷处理后的工件可达到技术要求,即抗拉强度≥1420 MPa,硬度≥42.5 HRC,安装面平面度≤0.5 mm。此外,在真空淬火炉中可通过调节淬火油温度,延长充气预冷时间等措施实现尺寸控制。 相似文献
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F. A. Vorontsov-Vel'yaminov 《Metal Science and Heat Treatment》1994,36(3):144-147
The replacement of quenching oils by ecologically pure polymeric quenching media that exhibit the necessary service properties and cooling capach ty is an urgent problem of the heat treatment of machine and tool components.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 3, pp. 15–17, March, 1994. 相似文献
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P. V. Sosnovskii 《Metal Science and Heat Treatment》1997,39(7):292-295
The international standard ISO 9950: 1995 (E) has been put into action for oils, and an analogous document is being worked
on for synthetic quenching media. In this connection, it is important to determine the requirements to be imposed on these
media for evaluating and controlling their parameters in order to provide the requisite quality of heat treatment. The present
paper describes the results of a study of the properties of the polymer quenching medium UZSP-1 conducted with the aim of
developing specifications for the medium.
Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 17–20, July, 1997. 相似文献
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《International Heat Treatment & Surface Engineering》2013,7(2):56-60
AbstractNanofluids are colloidal suspensions of nanoparticles in base fluids. Some of the particles used in recent research are metal oxide and carbide particles, such as SiC, CuO, Al2O3 and TiO2, graphite and carbon nanotubes and particles. Quenching in such colloids results in better cooling abilities, higher impact toughness and smaller dimension changes of steels, compared with pure quenching media. In this investigation, nanofluids with TiO2 powders of 50 nm average particle size were investigated. Base fluids of primary interest were deionised (DI) water, some commercial quenching oils and polyalkylene glycol water solution of various polymer concentrations, 5–30 vol.-%. The investigated fluids were prepared with the addition of the same TiO2 powder with different concentrations, from extremely low, 10 mg nanopowder per litre to 1 g L?1. The cooling characteristics of these colloids were compared with the results of base fluids, but also with the results of previous measurements carried out on the fluids with addition of Al2O3 micrometre and submicrometre size particles. All of the cooling curves were measured and recorded by the IVF Smart Quench system using a stainless steel probe of 12·5 mm diameter in accordance with ISO 9950 standard. The cooling rate (CR) versus temperature and time was compared for all of the investigated media. The preparation of fluids was conducted with great care, with respect to mechanical stirring and sonification times. The average particle size was measured for each case. In order to better understand the phenomena that occur during the quenching process, a high speed camera was used for recording the experiments. Titanium oxide nanoparticles show the most significant effects on the cooling properties of the water based polymer solution. The maximum cooling rate increases with higher particle concentration. When comparing the results of experiments with alumina particles, smaller and thermally less conductive TiO2 particles show greater effects on nanofluid properties. 相似文献
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通过热轧及轧后热处理试验研究了不同工艺对油井管用V140试验钢的力学性能和显微组织的影响,并探讨了Nb对试验钢组织及力学性能的作用。结果表明,高温下析出的Nb(C, N)可以抑制奥氏体的再结晶行为,使精轧过程可在未再结晶区进行,起到细化晶粒的作用,从而提高试验钢的强度与韧性。轧后空冷-离线调质、轧后快冷-回火和轧后快冷-离线调质3种工艺下试验钢的组织均为回火索氏体,组织均匀,力学性能优良,且轧后快冷-回火工艺可以满足V140钢的性能要求,还可以缩短生产流程、节约成本。此工艺的最佳回火温度为660 ℃,回火时间为30 min。 相似文献
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总结了大型锻件旋转锁定螺杆的研制过程,冶炼时合理配比化学成分,采用正火+调质的热处理方式和水淬油冷的冷却方式,使旋转锁定螺杆的各项性能指标均满足技术要求。 相似文献