共查询到18条相似文献,搜索用时 187 毫秒
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浅谈淬火介质冷却性能的测试 总被引:1,自引:0,他引:1
介绍了淬火介质冷却性能的测试方法,并分析讨论了JB/T 7951-2004《测定工业淬火油冷却性能的镍合金探头实验方法》和SH/T 0220-1992《热处理油冷却性能测定法》两个淬火介质冷却性能测试标准在执行过程中存在的一些问题、测试误差的分析及标定的方法. 相似文献
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建立了淬火油冷却性能的数字化模型.通过试验确定,符合国际标准ISO 9950:1995的国标GB/T 30823-2014/ISO 9950:1995《测定工业淬火油冷却性能的镍合金探头试验方法》(热电偶在探头心部)可以被采用.按中国石化行业标准SH/T 0220-92(热电偶在银探头心部)和日本标准JIS K2242... 相似文献
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稀土淬火油的开发与应用 总被引:1,自引:0,他引:1
介绍了淬火油稀土催冷添加剂的合成与调合工艺以及对淬火油理化性能、冷却性能和淬火工艺性能的影响。在淬火油中添加一定比例的稀土油溶性添加剂可明显改善淬火油冷却性能,工件采用该油调质淬火可提高其综合机械性能。 相似文献
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尽管以往已有过关于多种植物油的淬火冷却性能的报道,但有关防老化剂对这些油的耐氧化性和初期淬火冷却性能的影响的报道却不多见。本文评估了两种饱和度有很大差异的常用油即大豆油和棕榈油,其相对耐氧化性对淬火冷却性能的影响,并测定了常用的市场有售的常用防老化剂对这些油的防老化效果。除了测定相对耐氧化性外,还通过冷却曲线分析进一步评述了防老化剂对大豆油和棕榈油的初期淬火冷却性能的影响。 相似文献
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HideoYOKOTA KatsumiICHITANI KazuyoshiYAMAMOTO HiroyukiIKUMI YasufumiSUGIURA MichiharuNARAZAKI 《材料热处理学报》2004,25(5):447-452
Technical committee for Japanese industrial standard of heat treating oils has studied on the new method for testing cooling power of aqueous quenchants. This method employed the cooling curve test of a new sliver rod probe,which has a metal-sheathed thermocouple at its geometrical center. The experimental study has clarified that this probe has the higher sensitivity and excellent durability. In order to standardize this probe for cooling power test of aqueous quenchants, the repeatability and reproducibility of test results etc. have been studied. D.O.P. (Di-2-ethylthexyl Phthalate)was used as reference quenching fluid for initial calibration and for periodic calibration verification of the probe and system.In addition, 10% brine was used to check the response capability of the probe and system to the sudden change of temperature. These procedures are established according to the experimental investigation. This new test method is going to be built in the revised version of JIS K 2242 “Heat treating oils” as the cooling power test method for aqueous quenchants. 相似文献
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《International Heat Treatment & Surface Engineering》2013,7(1):15-18
AbstractQuenching is the most common method of hardening metals and involves continuous cooling from a given austenitising temperature to achieve full transformation into a martensitic structure. The cooling rate depends mainly on the thermal characteristics of the metal, the section thickness of the workpieces and the heat removal properties of the quenching medium. Oils, when used as quenching media contain a base oil and different types of additives according to the application requirements. As the base oil, it is possible to use mineral, synthetic and natural oils, either separately or in combination. Mineral base oils are widely used because of their advantages in stability in comparison with natural oils, or lower price in comparison with synthetic oils. There are numerous additives available for use but, besides functional properties, the environmental and safety requirements have to be considered in their selection, e.g. barium additives must be replaced with less harmful compounds. Additionally, petroleum derivatives should be replaced by renewable base stocks that are biodegradable, which is a general trend in lubricant development. By changing the composition of the base oils and additives, heat transfer characteristics are also changed. This study presents the results of the analysis of physical and chemical properties, as well as of cooling characteristics of new quenching oils with different compositions. Cooling curves have been evaluated according to ISO 9950 standard. 相似文献
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MichiharuNARAZAKI MamoruTAJIMA ShigeruASADA KatsumiICHITANI HideoYOKOTA MitsuguTANAKA YouichiWATANABE 《材料热处理学报》2004,25(5):437-442
Working group on cooling power test of quenchants of Japanese Heat Treatment Society hits studied on the new method for testing cooling power of aqueous quenchants. This method employed the cooling curve test of a new sliver rod probe, which has a metal-sheathed thermocouple at its geometrical center. The experimental study has clarified that the new silver probe has more excellent durability than the JIS silver probe employed for cooling power test of heat treating oils (JIS K 2242) and an aluminum alloy probe. Good repeatability, and reproducibility of the cooling curves during polymer quenching have been confirmed. This new method is useful especially for cooling power test of aqueous quenchants used for solution heat treatment of aluminum alloys. This new silver rod probe is expected to be adopted for the revised version of JIS K 2242 as the cooling power test method for aqueous quenchants. 相似文献
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Rafika Ikkene Zahia Koudil Mohammed Mouzali 《Journal of Materials Engineering and Performance》2014,23(11):3819-3830
The present paper discusses the influence of experimental conditions on the quenching performance of poly(2-ethyl-2-oxazoline) (PEOX) aqueous solutions used as cooling medium, using a standard ISO Inconel alloy probe for measurements of cooling rate. The evaluation procedure is demonstrated on characterization of cooling power of water-based polymer (PEOX) solutions by using different concentration, temperatures, and agitation conditions of the cooling media. The results show that the different experimental conditions have a significant effect on the cooling performance. The polymer quenching mechanism and the comparative cooling characteristics of water, and water-based PEOX polymer solution with concentrations from 2.5 to 15 wt.% were discussed. The study involved the assessment of the quenching severity by calculating the hardening power (HP) via empirical equations. Calculation of heat transfer coefficients as well as prediction of microstructural constituents and the hardness profile in a cross-section of steel sample were carried out on the basis of inverse calculation from the recorded cooling curve. 相似文献
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G. Ramesh 《International Heat Treatment & Surface Engineering》2014,8(1):24-28
AbstractIn this present work, the effect of the thermophysical properties of quenchants on its cooling performance was investigated. Water, brine solutions, polymer solutions and mineral oils were chosen to have quench media with varying thermophysical properties. Cooling curve analyses were carried out by using standard ISO/DIS 9950 quench probe. Grossmann H quench severity of the quench media was determined from the relation of H and cooling rate. Cooling curve analysis results showed that the change in thermophysical properties of the quench media had significant effect on the cooling history of the quench probe. The viscosity of the quenchant used for immersion quenching is the most important factor that controls the cooling performance of the quenchant compared to thermal conductivity of the quench medium. 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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淬火介质的冷却特性曲线究竟说明了什么 总被引:4,自引:3,他引:1
张克俭 《热处理技术与装备》2007,28(2):25-28
在用标准测试仪检测淬火介质冷却特性的同时,用摄像机摄录了探棒周围的状况.对比发现,按测得的冷却特性曲线的形状划分的冷却阶段,与探棒表面实际发生的冷却情况大不相同.说明了产生这种差异的原因.通过分析和推理,得出了结论:不能从淬火介质的冷却特性曲线去划分探棒所处的冷却阶段;凭测出的冷却特性曲线不可能准确推算实际工件可能获得的冷却情况;淬火介质的冷却特性曲线只宜用在介质冷却特性的相互对比中. 相似文献
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用标准探棒检测出的油或者水的冷却速度曲线既不能反映探棒表面的冷却情况,也不能用来推测工件表面的冷却过程。因此,应直接观测工件的冷却过程。淬火冷却过程的直接观测和研究发现,除了淬火介质的冷却能力和工件某部位的有效厚度之外,不同工件表面蒸气膜内气体的流动状况和工件表面从蒸气膜向沸腾冷却方式转型的次序,对工件表面的冷却速度和整个工件的冷却均匀性都有很大影响。业已揭示了后两种新因素影响工件冷却速度和冷却均匀性的基本规律,从而可以在淬火冷却过程中对同一工件表面的不同部位的冷却速度分别加以控制,这种控制技术被称为精细淬火冷却技术。 相似文献