高速钢深冷处理技术的研究现状及应用展望

概述了金属材料深冷处理及其作用机理,并主要介绍高速钢深冷处理的发展过程、国内外研究现状,并提出了一些深冷处理技术工业化的看法和展望.     

金属材料深冷处理技术研究进展

深冷处理作为一种有效提高材料性能的工艺,其研究已经从黑色金属领域走向有色金属。综合现有文献,总结了金属材料及其合金深冷处理的研究进展,简述了深冷处理技术的工艺和机理,并结合国内外研究现状提出了一些展望。     

深冷处理方法扩展应用的研究

对金属材料进行深冷处理,进而改善材料的力学性能,并可使其耐磨性能大大提高。在这一研究的基础上,探索金属材料深冷处理技术的扩展与应用,通过对砂砖型模深冷处理工艺的研究与实践,提出了深冷处理扩展技术应用方法和提高效益的途径。     

非晶合金深冷循环处理研究进展

非晶合金具有高强度、高硬度、大弹性极限等优异性能,是一种很有应用前景的先进金属材料,但较差的室温塑性严重制约其广泛应用。深冷循环处理作为一种简单有效的非晶合金室温塑韧性改善方法,受到学者们广泛关注。本文主要综述了非晶合金深冷循环处理相关研究成果,总结了不同深冷循环处理参数和样品因素对于非晶合金深冷循环处理效果的影响,并对非晶合金深冷循环处理技术的发展进行了展望。     

液氮深冷处理的应用研究

0 前言 深冷处理作为热处理工艺冷却过程的延续,在1939年由俄国人首次提出。当时只是一种理论上的探讨。由于当时低温技术尚不完善,在很长时间内只是在实验室进行摸索,证明了金属材料在低温下进一步相变的可能性。直到本世纪70年代,由于液态氮的广泛应用及绝热材料的发展,才由低温处理金属材料向更低温度发展创造了条件,使得深冷工艺应用于生产成为可能。1 深冷处理的研究成果及发展方向 目前,国外特别是美、日、英、俄罗斯等国家都在积极进行该工艺及装备的研究,并把这一技术应用到金属材料的热处理领域,涉及的材料已由过去单一的工     

深冷处理改善金属焊接接头力学性能研究现状

深冷处理对提高金属材料的强度、硬度、耐磨性和尺寸稳定性等力学性能能够起到积极作用,因而广受关注.针对焊接构件中普遍存在的焊接接头软化问题,综合现有文献资料,总结了采用深冷处理工艺来提高焊接接头力学性能新方法的国内外研究现状.     

深冷处理对黄铜电阻率的影响

利用电阻率测试仪测试了深冷处理前后黄铜在25～600℃的电阻率,并探讨了深冷处理对黄铜电阻率的影响.结果表明:深冷处理前后黄铜的电阻率均随温度的升高而增大,当温度低于300℃时,深冷处理后黄铜的电阻率大于深冷处理前的电阻率;高于300℃时,深冷处理后黄铜的电阻率小于深冷处理前的电阻率.     

高速钢循环深冷处理工艺及机理研究

采用正交试验法对W6Mo5Cr4V2高速钢循环深冷处理工艺进行了研究,分析了不同深冷工艺参数对力学性能的影响,并使用TEM观察了循环深冷处理前后的微观组织.结果表明,回火次数对力学性能影响最大.其次是深冷循环次数,最后是深冷时间.深冷处理后在马氏体孪晶带上有超细碳化物析出,多次循环深冷处理后.碳化物数量增加.与-次长时间深冷处理相比,在深冷时间足够的情况下,采用多次循环深冷处理工艺效果更好.     

硬质合金的深冷处理工艺及其研究进展

简要介绍了程控深冷处理装置,分析探讨硬质合金深冷处理工艺的基础理论研究;综述了目前硬质合金深冷处理的应用现状及其研究进展,并展望了硬质合金深冷处理的发展前景及发展方向。     

深冷处理对CuZnAl合金热膨胀系数的影响

利用膨胀仪测试了深冷处理前后CuZnAl合金在不同温度下的热膨胀系数,探讨了深冷处理对CuZnAl合金热膨胀系数的影响.结果表明:在25～800℃,经深冷处理后CuZnAl合金的热膨胀系数高于深冷处理前CuZnAl合金的热膨胀系数,且深冷处理后的dL/L与T基本呈线性关系.     

FeCrAIW电弧喷涂层组织的致密化研究

采用激光辐照对FeCrAlW电弧喷涂层的组织进行致密化处理,借助扫描电镜和X衍射对涂层的组织进行了分析.测试了涂层的显微硬度.结果表明:涂层组织致密度提高,孔隙率明显降低.随着激光扫描速度的增加,涂层的显微硬度降低.在较低的扫描速度下,涂层与基体之间形成互熔区,涂层与基体之间产生良好的冶金结合.     

Prospects of the Use of Synergetic Approach to Solution of Problems of the Science of Nanomaterials

A synergetic approach to solution of problems of self-controlled synthesis of nanostructures and creation of self-organizing nanotechnologies is considered in connection with the superproblem of creation of materials with functional properties resembling those of biosystems. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 55 – 61, July, 2005.     

Analysis of microporous structure of carbon adsorbents in terms of the theory of volume filling of micropores

A methodology of using the theory of filling the volume of micropores when evaluating the porous structure of carbon nanomaterials and adsorbents, as well as describing the adsorption of different species, is considered. Potentialities of the mathematical means of a theory of filling the volume of micropores when differentiating homogeneous and irregular microporous structure of activated carbon, determining the micropores’ parameters (their volume and size), evaluating the degree of heterogeneity of microporous structures, and describing adsorption over wide concentration range are analyzed. The perspectives of this approach, based on the theory of filling the volume of micropores, in the prognosis of the microporous structures’ parameters and the activated carbons’ adsorbability in the process of their synthesis are demonstrated. Original Russian Text ? G.A. Petukhova, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 2, pp. 170–176.     

Features of hardening of the heavy rolls of mills for cold rolling of tubing

All-Union Scientific-Research Institute for the Tube Industry, Chelyabinsk Tube Rolling Plant. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 9, pp. 42–43, September, 1989.     

Features of formation of the structure in production of blanks of disks of heat-resistant nickel alloys

Conclusions To provide a high level of mechanical properties in wrought blanks of cast ÉP741NP and ÉP962 alloys it is necessary to form controlled structures. A necklace-type structure formed in homogenizing isostatic treatment, subsequent thermomechanical working including alternation of the operations of deformation in the (+)-area and recrystallization anneals, and final heat treatment is preferable. The temperature conditions of all stages of thermomechanical working are strictly controlled, especially the final operation of deformation and heating for hardening. To eliminate hardening cracks and distortions it is necessary to use molten salts at t=600°C as quenchants. The use of multiple production operations makes it possible to significantly reduce the structural inhomogeneity related to inhertance of the original dendritic structure. However, the structure of the final semifinished product is nevertheless characterized by a difference in occurrence of the processes of polygonization and recrystallization between the former dendritic cells and the interdendritic spaces in deformation and heat treatment.To obtain structurally homogeneous blanks for gas turbine engine parts it is necessary to use basically new methods of remelting such as vacuum double electrode remelting and electron beam remelting with an intermediate vessel.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 25–29, December, 1991.     

飞机水平安定面后梁中段裂纹原因分析

在使用过程中,飞机水平安定面后梁中段出现裂纹。通过宏微观形貌观察、微区成分分析、金相检查和硬度测试,确定了水平安定面后梁中段的裂纹性质及失效原因。结果表明:后梁中段裂纹性质为剥层腐蚀裂纹,水平安定面后梁中段铆钉区腹板与后梁下缘条之间以及凸台与机身之间发生磨损导致剥层腐蚀裂纹。建议水平安定面后梁中段铆钉区腹板与后梁下缘条之间以及凸台与机身之间连接增加垫片,防止直接接触,并且对材料进行表面防护。     

Analysis of plastic bending of adhesive-bonded sheet metals taking account of viscoplasticity of adhesive

The present authors proposed a new technique of plastic bending of adhesive-bonded sheet metals. In this process, large transverse shear deformation occurs in the adhesive layer, which in some cases would induce the geometrical imperfection (so-called ‘gull-wing bend’) and the delamination. Since the strength of the adhesive is highly rate-sensitive, the amount of shear deformation of the adhesive layer and, as a result, ‘gull-wing bend’, are strongly influenced by the forming speed. In the present work, the effect of forming speed on the deformation characteristics of adhesively bonded aluminium sheets was investigated by performing V-bending experiments with various punch speeds at room temperature. In order to discuss the effect quantitatively, the numerical simulations for the bending were also conducted using a rate-dependent constitutive model of plasticity for the adhesive. Consequently, it was found that the large shear deformation and ‘gull-wing bend’ are suppressed by high-speed forming since the deformation resistance becomes higher at high strain rate.     

镁海水电池阳极活化机理研究

研制了新型Mg-Hg-X合金阳极材料,用扫描电镜(SEM)、能谱、X-射线衍射(XRD)和电化学测试等方法分析了镁合金阳极材料在海水介质中腐蚀前后的微观结构、表面形貌及表面元素的组成,研究了Mg-Hg-X合金阳极的溶解过程及活化机理.结果表明:在放电初期,Mg-Hg-X合金阳极材料中的第2相粒子随点腐蚀的发生直接脱落,形成腐蚀坑,随后Mg-Hg-X合金阳极溶解在介质中的合金元素离子与基体镁发生反应,再沉积于镁阳极材料表面的点蚀孔中,形成Hg、X的沉积层,破坏钝化膜的结构,降低了Mg-Hg-X合金阳极极化.使电极电位负移,同时沉积的具有高析氢过电位的Hg、X抑制了析氢腐蚀.     

车轮拉伸试样加工尺寸测量不确定度分析

对车轮拉伸试验的加工尺寸测量不确定度的来源进行了分析，通过建立数学模型和重复性试验评定了金属材料室温拉伸试验的测量不确定度。结果表明：作为规范化的检测实验室，在人员、机器、原料、方法、环境和管理等受控以及包含因子k为2的条件下，采用的评定方法可为金属材料室温拉伸试验测量不确定度评定。评定结果表明：在150 mm测量范围内最大允许误差不超过±0.04 mm，示值误差测量结果的扩展不确定度μ为0.04 mm，k为2。     

Kinetics of the oxidation of metals — Influence of self-diffusion of metal

The importance of the self-diffusion of a metal during its oxidation by a gas is treated for the cases of nonstoichiometric oxides having either interstitial cation or cation vacancies. We have established a general relationship for the reaction rate when a mixed diffusion process occurs. From this relationship, we have shown that the pressure dependence can be different, according to whether the rate-determining process is the self-diffusion through the metal or through the product.