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铁及钛合金以其[质量]密度小、强度高、耐高温、耐蚀性能好等突出优点,在民用医药、化工、石油等行业得到广泛应用.但各部门对材料性能的要求不同,因而用于压力容器制作的钛及合金的种类不断扩大,焊接工艺评定数量不断增多.为科学认识钛及合金的各项性能和正确使用钛及钛合金,减少焊接工艺评定数量,提高工艺评定质量,提高生产效率,减少不必要消耗,对压力容器用钛及合金有关性能进行分析是十分必要的.1焊接工艺评定焊接工艺评定是压力容器制造中衡量其制造水平的重要标志.它主要通过间接性试验,如大学性能试验(拉伸、弯曲、韧… 相似文献
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钛合金激光焊接的气体保护与焊前清理 总被引:5,自引:0,他引:5
钛及钛合金以其许多独特的性能优势,目前已得到世界各国的普遍重视,并获得了广泛应用.这一方面证明了钛合金的巨大用途,另一方面也预示着钛合金材料开发研制的光辉前景.为进一步提高其质量,扩大其应用范围,对钛合金的各种加工处理工艺也正处于改进与完善之中. 本文概述了钛合金的焊接现状,提出了钛合金试件清理与气体保护的方案,自行设计加工了用于钛合金激光焊接的专用夹具和惰性气体保护拖罩,并提出了初步检验钛合金激光焊接接头质量的方法,对钛合金激光焊接的试验研究与工程实践会起到一定的促进作用.l钛合金的焊接 通常情… 相似文献
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概述了表面纳米化技术及焊接接头表面纳米化的研究进展,分析了目前钛及钛合金焊接接头性能研究存在的问题与不足。表面纳米化技术能够降低焊接接头的应力集中,调整焊接残余应力场;细化晶粒,改善组织形态,实现组织均匀化;提高疲劳强度,延长疲劳寿命;对硬度和耐磨性等也能产生有利的影响。展示了钛合金焊接接头表面纳米化的研究意义与应用前景。 相似文献
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1钛容器的无损检测钛容器无损检测法涉及的标准有国家标准(GB)和机械行业标推(JB),分别如下:GB5193-85钛及钛合金加工产品超声波探伤方法;GB厂12969.1一则钛及铁合金管村担声波检验方法;GB厂12969.2-gi铁及钛合金管材涡流检验方法;GB5677铸钢件射线照相及底片等级分类方法;JB4730-94压力容器无损检测.2容器用钛村的无损检测()GB厂7621-94“钦及钛合金板材’中求对钛板的无损检测作任何规定,起不中的“钛制焊接容器”标准中规定:饮板厚度等于或超过20mm时应要求超声波探伤合格,方法按GB5193,合格级别由设计规… 相似文献
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钛及钛合金综合性能优异,但由于高温活性强导致焊接氧化问题严重,特别是在很低的固态温度下仍然吸收气体影响焊接接头质量,因此需要严格的焊接保护措施.在分析了钛合金的氧化机理及特性的基础上,系统总结了焊接过程中的各种防氧化保护措施和具体技术.详细介绍了钛合金长直焊缝、环形焊缝、空间不规则焊缝以及增材制造四种典型过程的防氧化保护问题,主要的防护措施有保护拖罩、封闭式充氩环境以及强制冷却三大类.针对钛合金长直焊缝局部气体保护,一般形式为保护拖罩结合背面保护气槽以及水冷措施;对于环形焊缝的背面保护方式,可以采用背面拖罩或者整体充氩保护的方法,其正面保护采用弧形拖罩即可;而不规则焊缝受限于空间形状,焊接拖罩的方法不再适用,小尺寸构件可采用简易充氩保护箱,大尺寸构件保护问题亟待解决;增材制造过程中的热积累问题也对其保护形式提出了更高的要求,目前采用具有一定气体挺度的层流惰性气体和CO2跟随强制冷却的方式取得了较好的效果. 相似文献
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钛合金窄间隙TIG焊技术研究 总被引:1,自引:0,他引:1
在介绍窄间隙焊接的优越性和钛合金各种焊接方法的基础上,着重介绍了俄罗斯中央结构材料研究院研制出的一种应用于钛合金的窄间隙TIG焊接技术,并分析了该技术的优缺点、工艺特性及此工艺下的啮合强化效应,分析并讨论了产生此强化效应的原因。 相似文献
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K. S. Senkevich S. V. Skvortsova I. M. Kudelina M. I. Knyazev V. V. Zasypkin 《Russian Metallurgy (Metally)》2014,2014(1):66-70
The effect of a structural type (lamellar, fine, gradient) and additional surface alloying with hydrogen on the diffusion bonding of titanium alloy VT6 samples is studied. It is shown that the surface alloying of VT6 alloy parts with hydrogen allows one to decrease the diffusion welding temperature by 50–100°C, to obtain high-quality pore-free bonding, and to remove the “structural” boundary between materials to be welded that usually forms during welding of titanium alloys with a lamellar structure. 相似文献
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Titanium alloys are widely used in the aerospace industry on account of their high strength, fatigue strength, impact strength, and corrosion resistance. Airplane components such as ribbed panels must satisfy strict requirements on the quality of weld joints and the dimensional precision. The welding of titanium alloys leads to the formation of flaws at the joint and impairs the performance of the part; their geometric dimensions are distorted on account of the welding stress; pores and microstress appear in the seam; and the mechanical and other characteristics are impaired. That calls for comprehensive analysis of the manufacture of ribbed titanium panels, all the way to the heat treatment of the final product, so as to discover the processes that are most likely to generate defects. The manufacture of the workpieces—including their preparation for welding, the welding conditions, and subsequent heat treatment—affects the static and cyclic strength of welded ribbed panels, with variation in the number of weld-seam defects and their total area. The results obtained in the present work permit prediction of the properties and reliability of welded structures and the maintenance of identical properties of the basic metal and the seam metal, with the guaranteed absence of external and internal effects, on the basis of the selected production processes. It is found that the properties and reliability of weld joints will match those of the basic VT20 titanium alloy in ribbed panels in the following conditions: welding with specific cooling rate in the phase-transition temperature range; final milling, turning, degreasing, and drying of the surface of the joined edges; light annealing after welding in air; subsequent sandblasting; and gas-laser layout cutting in a nitrogen or argon atmosphere, with or without milling. 相似文献
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金属钛的性能、发展与应用 总被引:3,自引:0,他引:3
介绍钛金属的性能和分布情况,反映钛工业的发展和现状,叙述钛金属的冶炼原理,阐述钛金属及合金的重要应用,探讨耐蚀性的表面处理技术.最后介绍我国钛工业目前的大致情况。 相似文献
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JW McDonald SP Althomsons KL Hyrc DW Choi MP Goldberg 《Canadian Metallurgical Quarterly》1998,4(3):291-297
STATEMENT OF PROBLEM: Titanium and its alloys are more commonly used in prosthodontics and welding has become the most common modality for their joining. Studies on the welding of titanium and its alloys have not quantified this value, though its importance has been suggested. PURPOSE: This study compared the strength and properties of the joint achieved at various butt joint gaps by the arc-welding of cast Ti-6Al-4V alloy tensile bars in an argon atmosphere. MATERIAL AND METHODS: Forty of 50 specimens were sectioned and welded at four gaps. All specimens underwent tensile testing to determine ultimate tensile strength and percentage elongation, then oxygen analysis and scanning electron microscopy. RESULTS: As no more than 3 samples in any group of 10 actually fractured in the weld itself, a secondary analysis that involved fracture location was initiated. There were no differences in ultimate tensile strength or percentage elongation between specimens with weld gaps of 0.25, 0.50, 0.75, and 1.00 mm and the as-cast specimens. There were no differences in ultimate tensile strength between specimens fracturing in the weld and those fracturing in the gauge in welded specimens; however, as-cast specimens demonstrated a higher ultimate tensile strength than welded specimens that fractured in the weld. Specimens that fractured in the weld site demonstrated less ductility than those that fractured in the gauge in both welded and as-cast specimens, as confirmed by scanning electron microscopy examination. The weld wire showed an oxygen scavenging effect from the as-cast parent alloy. CONCLUSIONS: The effects of the joint gap were not significant, whereas the characteristics of the joint itself were, which displayed slightly lower strength and significantly lower ductility (and thus decreased toughness). The arc-welding of cast titanium alloy in argon atmosphere appears to be a reliable and efficient prosthodontic laboratory modality producing predictable results, although titanium casting and joining procedures must be closely controlled to minimize heat effects and oxygen contamination. 相似文献
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钛合金的腐蚀机理及耐蚀钛合金的发展现状 总被引:2,自引:0,他引:2
钛及钛合金作为耐蚀结构材料在腐蚀工程中的应用已越来越广泛。综述了钛合金在不同腐蚀介质中的几种腐蚀行为及其腐蚀机理,概述了不同合金化元素的添加对钛合金耐蚀性能的影响及其作用机理,最后介绍了耐蚀钛合金的发展现状,以及今后耐蚀钛合金研究的发展方向。 相似文献
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