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柴玉成 《机械制造文摘:焊接分册》2018,(5)
介绍火电厂高压导汽管ZG15Cr2Mo1弯头法兰与1Cr11MoV内套管的异种钢焊接工艺,包括弯头法兰更换的焊前准备、焊接工艺及检验方案等。结果表明,焊后对焊缝进行检验未出现异常,该焊接工艺能够保证焊后高压导汽管的安全运行。 相似文献
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高压汽轮机的汽缸前部是汽轮机的重要部件之一,它由汽缸壳体、上下喷咀室,蒸汽室、进汽管与法兰等组成(图1),材质均为20XM合金钢,其中汽缸壳体、喷咀室与蒸汽室为铸钢件,进汽管为压制钢管,法兰为锻件。由于高压汽缸须承受高温(480℃)高压(90大气压),所以对焊接质量要求比较严,在焊接处不允许有砂眼、气孔、夹渣与裂纹等缺陷。 相似文献
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ZF—220高压断路器中,各类A3钢法兰圈和1Cr18Ni9Ti不锈钢隔磁块的焊接,加工复杂,焊接量大,不锈钢焊条价格昂贵。一般情况下,一块长70毫米、厚32毫米的隔磁块,二侧与法兰圈焊接,一条焊缝约用去不锈钢焊条20根,计1.5公 相似文献
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重型H型钢在跨海桥梁、钻井平台等高层建筑和大型设施有广泛应用。为推动马钢高强度厚规格重型H型钢的品种开发,对UB356 mm×406 mm×634 mm规格、S450 J0牌号H型钢进行了试制。厚重规格H型钢由于压缩比较小,采用普通生产工艺较难使其获得较高的强度,需要轧后采用快速冷却工艺,研究了4种QST(淬火+自回火)工艺对所试制H型钢翼缘组织性能的影响。结果表明:经QST工艺处理后, H型钢翼缘厚度方向出现了明显的组织分层现象,第1类为表面淬硬层回火索氏体组织,第2类为心部铁素体+珠光体组织;随着回火层厚度的增加,温度逐渐升高,回火组织中马氏体位向逐渐消失,颗粒状的碳化物逐渐长大,心部组织晶粒尺寸也逐渐增大;不同QST控冷工艺下H型钢翼缘回火层厚度不同,当水压、水嘴组数一定时,随着辊道速度的增加,回火层厚度呈现逐渐减小的趋势;近翼缘外表面的回火层硬度变化趋势呈现先增大后减小的趋势,靠近翼缘内表面的回火层硬度呈现逐渐减小的趋势。在4种QST工艺下,只有水压1.3~1.4 MPa、水嘴数开16组、辊道速度0.8 m/s的条件下所试制的重型H型钢力学性能满足技术要求,且富裕量较大。 相似文献
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为研究Q800高强钢焊接工字形截面的纵向残余应力分布规律,采用线切割法对4个试件进行试验研究,分析腹板和翼缘板件宽厚比对残余应力的影响,研究各板间残余应力的相互影响及其自平衡性,提出Q800高强钢焊接工字形截面的残余应力分布模型和计算公式. 结果表明,Q800高强钢工字形截面的残余应力分布形式与普通强度钢材的一致. 焊缝和火焰切割边附近呈现残余拉应力,且随着宽厚比的变化呈不规律变化;翼缘外伸部分中部和腹板中部都呈现基本恒定的残余压应力,且随着板件宽厚比的提高而相应减小;其余部位是从残余拉应力到残余压应力转变的过渡区域;翼缘和腹板内的残余应力基本满足自平衡条件,二者没有相互间的影响作用. 相似文献
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Heng-Sheng Lin Chih-Wei Tung 《International Journal of Machine Tools and Manufacture》2007,47(14):2133-2139
Hole flanging with cold extrusion can avoid necking or fracture as encountered in conventional sheet metal-forming operations. Substantial flange height and lip thickness can be achieved with flange extrusion because the forming load is compressive. Using a hydraulic press, flange extrusions of 5 and 10 mm inner diameters were produced in pieces of cup-shaped galvanized steel, as well as aluminum 5052 workpieces with a thickness of 0.8 mm, both of which had a pre-hole on the cup bottom. As the punch load was exerted on the cup rim, a clamping force was applied to suppress dilation on the cup bottom.The experiments showed that with sufficient clamping force, significant flange height could be extruded. The utmost extruded flange of 5 mm i.d. was 6 times larger than that drawn from the conventional method, whereas that of 10 mm i.d. was 3.8 times larger than that drawn from the conventional method. However, no flange was extruded and buckling occurred on the cup bottom when the clamping force was insufficient. The experiments confirmed the results predicted by the FE simulation. For a selected flange inner diameter, the ratio of the extruded flange height to the increase in cup bottom thickness was directly related to the normalized clamping pressure, i.e. the ratio of clamping pressure to workpiece yield strength. Therefore, both the application of a larger clamping force or the use of low-strength workpiece materials facilitated the extrusion of flange while suppressing the dilation of the cup bottom. Flange extrusions with a larger diameter correspond to a smaller extrusion ratio or reduction of area. Experiments showed that a significant flange height could be extruded with a 10 mm inner diameter for both galvanized-steel and aluminum 5052, while results for extrusions with a 5 mm inner diameter were unfavorable when using galvanized-steel. High-strength materials and a high extrusion ratio required greater clamping force for the flange extrusion process, and consequently caused excessive forming load on the forming dies as well as on the hydraulic press, thus rendering the process less effective. 相似文献
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0 IntroductionSteelconstructionisthebeststructureformagainstearthquakeforitsgoodmechanicalpropertiesandadaptability.Recentlydamagestosteelstructureonearthquakeshavebeenfrequentlyreported.BrittlefracturewasfoundonearthquakesofNorthridgeandHyogokenNanbu,… 相似文献
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不锈钢平焊法兰与不锈钢管件的固定运用TIG焊接技术,实行法兰密封面自熔焊接,法兰非密封面加丝焊接,以实现法兰连接功能。 相似文献
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采用V-N微合金化工艺,开发出了屈服强度490 MPa以上的高强门架型钢。针对生产过程中出现的冲击性能不合,采用V-Ti微合金化工艺后,冲击性能明显提升,最高达到102 J,原因是Ti的细化晶粒作用,但屈服强度有所降低,是因为TiN的生成减弱了V-N的强化作用。生产过程中在型钢翼缘尖部出现裂纹,在生产工艺基本不变的条件下,分析产生的原因是钢中N元素含量高,N与V和Ti等元素形成氮化物在晶界析出促进了方坯横裂纹的发生,采用V-Fe合金代替部分V-N合金后,有效消除了翼缘裂纹的产生。 相似文献