共查询到12条相似文献,搜索用时 93 毫秒
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大庆石化分公司炼油厂延迟焦化装置低温水-顶循换热器投用13个月,管束发生腐蚀穿孔。对换热器管束进行取样,从管体内壁腐蚀状况、管体材质金相组织、管体内壁涂层状态以及工艺操作几方面对泄漏原因进行了分析。根据分析结果,提出处理措施。目前换热器已完好运行4 a,证明该处理方式可行,效果显著。 相似文献
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上盖冲压工艺与模具设计 总被引:1,自引:1,他引:0
根据某上盖零件的结构特点及技术要求,通过对各工艺方案进行分析比较,设计了落料-拉深-冲孔-翻边复合模,即在一个工位同时完成落料、拉深、冲孔和翻边4个不同工序的复合模结构.详细介绍了模具的工作过程及设计要点,解决了条料的定位、导向、卸料、出件、优化模具结构等技术问题.经实际生产验证,此套模具大大提高了生产效率,其合理的模具结构保证了上盖的形状及尺寸精度,提高了企业的经济效益. 相似文献
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对于大断面柴油机气缸盖,通过采用顶置发热冒口,并配合使用冷铁,能最大发挥冒口作用。对于大型单体气缸盖,可采用平组立浇方式,增强顺序凝固作用,进一步缩小缩松风险。 相似文献
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Special features of the formation of welded joints in vertical laser-arc welding of low-alloy steels
ABSTRACTInvestigations were carried out into the special features of the technology of vertical laser-arc welding of large structures made of high-strength and low-alloy steels with a variable welding gap and a large root face.The parameters of the conditions of vertical laser-arc welding of root passes in the low-alloy steel 30–40 mm thick with a root face of 10 mm (welding speed, the amplitude and frequency of transverse oscillations, the intensity of welding current, arc voltage, laser radiation power) resulting in the formation of high-quality welded joints are determined. The experimental results show that the laser radiation power, required for producing continuous penetration of the root face, depends on the thickness of the parent metal: for the metal thickness of 14–30 mm the sufficient laser radiation power is 3.8 kW, for a thickness of 40 mm it is no less than 4.6 kW to penetrate a depth of 5 mm.The welded joints have a fine-dispersed acicular structure of the martensitic – bainitic type. The experimental results were used to develop a technology of welding of low-alloy steels of different thickness using robotic equipment. 相似文献
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根据50 t×35 m龙门起重机的实际运行工况,对其金属焊接结构进行了有限元分析和动态仿真分析,得到了各种工况下的应力分布以及力-时间历程;把静态应力与力-时间历程相结合,计算出动态应力.在此基础上,利用国际焊接学会提供的疲劳寿命S-N曲线,对金属焊接结构进行疲劳寿命分析,得出其疲劳寿命分布云图.结果表明:柔性腿上部变截面处为疲劳薄弱部位,节点5031疲劳损伤最为严重,寿命为1.09×106次循环. 相似文献