共查询到20条相似文献,搜索用时 109 毫秒
1.
李午申 《机械工人(热加工)》1999,(12):39-40
四、焊接裂纹的预测及诊断 焊接裂纹预测及诊断是焊接性研究最为重要的内容之一。但是裂纹的预测及诊断涉及的因素很多,只有具备丰富专业知识和实践经验的焊接专家才能胜任。但一般焊接工程师并不具备预测及诊断裂纹的丰富知识和经验,因此,往往需要进行大量焊接性试验才能解决问题,这势必造成人力、物力、财力的浪费,即便如此,一旦失误,将会造成不可估量的损失。 相似文献
2.
船舶铸钢件一般具有体积和截面尺寸大、形状复杂、所处工况恶劣、一旦损坏不易修复等特点。本文从解决铸钢焊接过程中和焊接后的裂纹问题入手,探讨合理、有效的焊接工艺方案,希望能为今后类似问题提供解决思路。 相似文献
3.
通过对lCr20Nil4Si12奥氏体耐热不锈钢的化学成分,力学性能及焊接性分析,制定了正确的焊接工艺并严格执行完全解决了攀钢冷轧厂罩式炉内罩修复过程中出现的焊接热裂纹问题。 相似文献
4.
依据多年来K合金与45风焊接出现裂纹的现象,分析产生理解纹的机理,进而从焊材选择、焊接工艺诸多方面采取对策,一举解决了产生裂纹的难题。 相似文献
5.
6.
为了达到防腐蚀目的,又考虑到制造成本,所以焦化分馏塔选用复合板16MnR OCr13A1。在焊接施工中的主要技术问题是复合板焊接材料的正确选用及焊接工艺的正确制定,制造过程中主要解决的问题是焊接裂纹、熔合区脆性、热影响区软化的预防及控制措施。 相似文献
7.
在组合机床的加工过程中,对于精加工铣削的铣头,常采用铣削后让刀,弹簧夹紧套抱紧主轴滑套的机构,而弹簧夹紧套的加工制造过程比较复杂,给加工工艺、焊接工艺带来很多困难,常在焊接及淬火后产生裂纹,造成漏油。通过对材料及焊接性能的分析,采用合理的工艺手段,解决了这些问题。 相似文献
8.
9.
工艺与微量元素对镍基合金焊接热影响区液化裂纹影响的研究进展 总被引:3,自引:0,他引:3
镍基合金因其优异的耐高温和耐腐蚀性,广泛地应用在航空航天、核电及海洋采油等行业。基于镍基合金的重要性,研究其焊接热影响区(Heat-affected zone,HAZ)液化裂纹问题对于促进该问题的解决具有重要意义。焊接工艺的好坏直接影响到镍基合金焊接性能,是导致其HAZ液化裂纹的重要因素之一。采用热处理工艺,可以获得预期的组织和性能,以降低液化裂纹敏感性。同时,合金母材中微量元素影响晶界非平衡偏析行为,会导致HAZ液化裂纹的产生。从焊接工艺、热处理工艺及微量元素三个方面综述镍基合金焊接HAZ液化裂纹的最新进展,并对液化裂纹的测试方法进行总结,对未来的研究趋势进行展望。 相似文献
10.
针对大直径不锈钢法兰拼焊时易产生焊接变形和热裂纹的问题,从大型法兰拼焊变形规律,焊接工艺等方面入手,分析了产生变形和热裂纹的原因,制定了相应的工艺措施,避免了焊接变形和热裂纹的产生,确保了产品质量,提高了生产工效。 相似文献
11.
12.
13.
LIU Wenyan LIU Jibin WANG Lai MU Wenguang HU Yinhong Research Development Center Wuhan Iron & Steel Corp. Wuhan China School of Materials Science Engineering Dalian Uniersity of Technology Dalian China 《机械工程学报(英文版)》2011,(3):433-438
The weldability of copper-bearing aging steel is evaluated using calculated cracking susceptibility index Pcm,oblique Y-groove cracking test,heat-affected zone (HAZ) maximum hardness measurement,submerged arc welding (SAW) test and gas metal arc welding (GMAW) test.The results show that this copper-bearing aging steel has low hardenability and cold cracking susceptibility.SAW test of 40 mm thick plate with WS03 wire matched by CHF101 flux reveals that the welded joints obtain high strength and good impact toughness at low temperature.The HAZ has no hardening but there exists a slightly softening phenomenon.Thus,line energy should be limited or controlled strictly to avoid softening behavior in HAZ during SAW.GMAW tests of 12mm and 24mm thick plates using WER70NH wire show that the tensile strength of joints reaches 720MPa,higher than the stipulated strength requirement of base metal.The average impact energy at-40℃ in the welded joints is more than 140J exceeding minimum stipulated requirement by a wide margin.There are no hardening and softening behaviors in the heat-affected zones of GMAW.All weld metals exhibit acicular ferrite (AF) plus small amount of proeutectoid ferrite (PF) structure,of which the former can significantly improve impact toughness of weld metal.The predominant microstructure in coarse grain HAZ is bainite. 相似文献
14.
15.
Xiaojie Wang Hui-Ping Wang Fenggui Lu Blair E. Carlson Yixiong Wu 《The International Journal of Advanced Manufacturing Technology》2014,73(1-4):73-85
In this paper, an experimental study combined with a numerical model consideration of both thermal conduction and fluid flow in the molten pool were carried out, aiming to analyze solidification cracking susceptibility of dual-beam laser welding on Al alloys. The maximum accumulated transverse displacement in the mushy zone was calculated based on the strip expansion technique and employed to evaluate centerline solidification cracking susceptibility. Numerical calculations showed that increasing inter-beam spacing in side-by-side dual-beam laser welding of Al alloys could lead to increased accumulated transverse displacement in the weld, resulting in higher solidification cracking susceptibility, which agreed well with experimental observations. The analysis results also showed that increasing the laser power or reducing the welding velocity increased hot cracking susceptibility. The optimum cracking-free welding condition for dual-beam laser welding of Al can be determined with the help of numerical modeling, in which the hot cracking susceptibility can be evaluated and numerically reduced by adjusting welding process variables. 相似文献
16.
17.
18.
探讨了高炉阀门冷焊用焊接材料和焊接工艺。生产实践证明,所选用的DF—2B型焊条和焊接工艺,常温下焊接时,可获得抗裂性和耐磨性良好的堆焊合金层,所焊阀体可以满足高炉使用性能要求。 相似文献
19.
对开裂的天然气集气末站汇管进行了宏观形貌、显微组织、化学成分分析和力学性能测试、断口形貌观察以及腐蚀产物相组成确定,对其开裂原因进行了分析。结果表明:集气末站汇管开裂裂纹位于汇管的焊缝区,裂纹分为表面裂纹与隐藏裂纹,裂纹性质属氢致开裂和应力导向氢致开裂;设备内壁防腐涂层质量低劣是导致开裂的主要原因,焊接工艺不当对开裂有明显的促进作用。 相似文献
20.
焊接前先对母材进行预热,可以减小焊后残余应力,防止冷裂纹。基于上述原因采用51单片机作为控制器,实现了对209T制动梁端轴焊接预热温度的检测和显示,实践证明该系统可靠性高,操作简便,提高了制动梁端轴的焊接性能。 相似文献