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DN1800特大整锻管模锻件相对壁厚极小、规格大、吨位重、火次多、拔长效率低、技术要求高,且现有生产工装辅具不匹配,在工艺设计、质量控制和生产组织方面难度极大。通过研究锻造拔长机理及过程,提出控拔控压工艺方案、拔长效率提升控制方案和Φ1900 mm芯轴拔长+上平下V形砧空收+Φ2200 mm上圆弧下V形砧复合空收成形工艺方案,并结合工艺性分析,建立了塑性变形有限元分析模型,不断优化工艺参数,通过提出生产操作关键点,细化空收工艺参数,严格进砧量、压下量、温度和旋转角度的匹配控制,成功完成特大整锻管模的试制生产,验证了工艺参数及成形工艺的合理性,积累了特大整锻管模特殊锻造成形经验。 相似文献
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通过分析特大型管板锻件内在变形机理及过程,采取两端半弧板、中间长弧板的成形工艺和宽砧强压拔方法锻制管板,成功完成了8 000 mm特大型管板锻件的生产试制。 相似文献
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轧机中的关键零件之一支撑辊在轧制设备运行的过程中承受轧辊传来的交变应力。大型支撑辊由大型钢锭锻造而成,但大型钢锭中存在种种缺陷,给支撑辊的质量带来很多问题。针对此问题,采用WHF法能够锻合锻件内部组织缺陷,可改善锻件质量。采用DEFORM软件,模拟WHF法拔长,研究WHF法在锻造拔长过程中对锻件心部的作用。实验研究表明,WHF法在拔长的第3道次时,锻件心部的应力状态由拉应力完全转变为压应力。同时,到第6道次后,锻件心部等效应变达到1.2。通过锻件心部压应力和等效应变值可知,WHF法能够完全破碎锻件内部的组织缺陷,生产出质量合格的支撑辊锻件。 相似文献
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轴类大锻件拔长可以采用V型砧、四砧径向锻造等。为了解这些拔长方式对锻件芯部变形的影响,应用有限元软件Super Form模拟了拔长锻造过程,对比分析了V型砧和四砧径向锻造两种工艺方法的锻透性。研究表明:V型砧拔长,锻后锻件内部等效应变分布不均匀,各处变形差异较大,经3道次拔长后,锻件芯部锻透性较好,给定条件下的累积等效应变约为1.6;四砧径向锻造,锻后锻件内部等效应变分布比较均匀,但锻件芯部锻透性较差,给定条件下芯部等效应变小于0.2,且端部一定长度范围内,芯部等效应变更小,经4道次拔长后,芯部累积等效应变为0.8左右。 相似文献
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A. A. Babakov 《Metal Science and Heat Treatment》1967,9(10):764-770
Conclusions Highly alloyed steels and alloys are produced in conformity with GOST or technical specifications in thick and thin sheets, beams and channels, bars, hot-rolled and cold-rolled pipe, and rod. Castings are produced in the specialized plant of the Ministry of Chemical and Petroleum Machine Building.The technology of welding stainless steels and alloys is given in [15] and [16].TsNIIChERMET. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 10, pp. 43–50, October, 1967. 相似文献
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模具渗硼工艺及其发展应用 总被引:4,自引:0,他引:4
渗硼是提高模具使用寿命的重要途径,是在金属表面形成高硬度的金属硼化层,显著提高其耐磨性,且具有良好的耐热性和耐蚀性。近年来,随着渗硼工艺逐步改进和完善,已发展了复合渗、多元共渗及低温渗硼工艺,取得了良好的经济效果。 相似文献
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A. Yu. Tsivadze G. V. Ionova V. K. Mikhalko 《Protection of Metals and Physical Chemistry of Surfaces》2010,46(2):149-169
The possibility of using unique properties of lanthanides in the nanotechnology is demonstrated. The origination of linear
and nonlinear optical properties of lanthanide compounds with phthalocyanines, porphyrins, naphthalocyanines, and their analogs
in solutions and condensed state and the prospects of obtaining novel materials on their basis are discussed. Based on the
electronic structure and properties of lanthanides and their compounds, namely, optical and magnetic characteristics, electronic
and ionic conductivity, and fluctuating valence, molecular engines are classified. High-speed storage engines or memory storage
engines; photoconversion molecular engines based on Ln(II) and Ln(III); electrochemical molecular engines involving silicate
and phosphate glasses; molecular engines whose operation is based on insulatorsemiconductor, semiconductor-metal, and metal-superconductor
types of conductivity phase transitions; solid electrolyte molecular engines; and miniaturized molecular engines for medical
analysis are distinguished. It is shown that thermodynamically stable nanoparticles of Ln
x
M
y
composition can be formed by d elements of the second halves of the series, i.e., those arranged after M = Mn, Tc, and Re.
Prospects of using lanthanide superconductors in nanotechnology are considered. 相似文献
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《稀有金属材料与工程》2006,23(4):23-26
结合近年来现场试验与施工实践,分析研究了中小型镍材(工业纯镍)设备与管道的特点、性能、焊接缺陷与产生原因,以及防止与消除其缺陷、优化制造施焊质量的工艺措施,并总结了若干条注意事项。 相似文献