共查询到20条相似文献,搜索用时 375 毫秒
1.
2.
不锈钢焊接构件的振动时效与热时效 总被引:6,自引:0,他引:6
采用振动时效和热时效两种方法对核电堆内构件304L不锈钢方形筒体(控制棒导向筒)进行焊后去应力处理。通过对残余应力和工艺变形测定。表明这两种方法都可达到期望的技术要求。对振动效的机理及动应力对去应力效果的影响作了较详细的介绍,并对两种工艺进行了比较。 相似文献
3.
振动时效技术是通过引起焊接构件的共振达到调整构件内部残余应力的新技术,具有适用性强、耗能低等特点,有着广泛的应用前景.本文通过测试采用不同振动时效处理工艺后海洋平台用D36钢焊接试件的焊后残余应力及角变形,对比分析了在焊接过程中不同阶段进行振动时效处理对焊接构件残余应力和角变形的影响.试验结果显示,采用“焊时振动”处理工艺时的角变形最小,而采用“层间振动”处理工艺可以获得最好的应力消除效果.为不同振动时效处理工艺应用于减小焊接构件残余应力和焊后变形提供了试验理论依据. 相似文献
4.
5.
6.
7.
作者论述了振动时效机理,并针对塔器产品铸件制定出合适的振动时效工艺。还对铸铁残余应力检测技术进行了大量试验,找出可行方案,并制定出振动时效工艺参数。同时,在微电脑扫频仪控制下,对振动期间动态参数进行监测,判断振动效果。采用振动时效工艺生产的塔器铸件,达到了消除应力和均化残余应力的目的。 相似文献
8.
针对焊接残余应力对结构性能的影响,介绍了几种消除残余应力的方法,建议采用振动消应VSR技术,消除岔管残余应力并采取磁弹法应力测试的方法,按照标准JB/T5926-1998《振动时效工艺参数选择及技术要求》进行残余应力消除率的评定。结果表明,振动消应VSR技术可有效地提高工作效率。 相似文献
9.
10.
11.
12.
In the present study, low transformation temperature welding wire (LTTW), which can induce residual compressive stress around 304L welded joints, has been developed to improve the fatigue performance of welded joints. Procedure of design and chemical composition of weld metal and deposited metal of LTTW are introduced. The microstructure of weld metal of LTTW is composed of low carbon martensite and residual austenite. The residual stress distribution of a single welding bead of LTTW was measured and the result shows that compressive residual stress is generated. In addition, fatigue test was also carried out on no-load cruciform welded joints of 304L stainless steel under three conditions: as welded, 308L dressing and LTTW dressing. The result shows that the fatigue life of LTTW dressing joints (2×106 cycles) is improved by 14–23 times and 3–6 times compared with that of as welded joints and 308L dressing joints. 相似文献
13.
采用埋弧焊方法,进行了304L不锈钢厚板的对接试验研究.通过对焊接接头处的组织观察,并结合焊接接头的-196 ℃冲击韧性以及不同退火条件下残余应力测试,分析了埋弧焊304L不锈钢焊接接头组织和性能. 结果表明,热影响区组织为奥氏体,焊缝区则为奥氏体与少量的铁素体的复相组织;采用残余应力盲孔释放测量方法对焊接接头进行测试,随着退火温度的升高,焊缝及热影响区的残余应力得到进一步的释放;冲击试验中,热影响区-196 ℃冲击吸收能量随退火温度的升高急剧下降,焊缝区-196 ℃冲击吸收能量则呈平稳下降趋势. 相似文献
14.
15.
以1Cr-0.5Mo合金钢水冷壁典型部件为对象,分析比较了水冷壁3种状况下(焊态、焊后热处理和振动时效)的焊接残余应力以及力学性能。采用优化后的振动时效工艺,焊接接头综合力学性能和显微硬度均能满足工艺评定需要,可考虑代替部分1Cr-0.5Mo钢管屏的焊后热处理。 相似文献
16.
采用热时效和振动时效两种工艺控制大型直缝焊管的焊接残余应力.结果表明,热时效和振动时效工艺均能有效降低Q345钢大型直缝焊管的残余应力,使焊接残余应力分布更加均匀,且焊接区的消应力效果相对于母材区更为明显.其中振动时效对铸态组织有良好的消应力作用,但对于冷塑性变形加工状的组织消应力效果不理想.热时效工艺的消应力效果和均化应力能力优于振动时效工艺,但在满足消应力要求的前提下考虑经济因素和工艺便捷性,最终选定振动时效作为消应力工艺. 相似文献
17.
采用弹塑性有限元法计算了Q235碳钢与304不锈钢的焊接温度场和焊接残余应力,计算结果表明,由于二者物理性能的差异造成了焊接温度场和残余应力分布的不均匀,焊接残余应力的峰值出现在304不锈钢一侧,其值略低于304不锈钢的屈服强度.当焊接热源偏向Q235钢时,焊接残余应力峰值变化较小,但高应力区减小,焊接变形明显减小,当焊接热源偏向304不锈钢时结果相反.当焊接热输入增大时会导致焊后高应力区范围的扩大,残余应力的峰值略有降低.采用红外热像仪测量了焊接过程中焊接接头上表面的温度变化情况,有限元计算的结果与其符合较好. 相似文献
18.
A. K. Roy A. Venkatesh V. Marthandam S. B. Dronavalli Douglas Wells Ronald Rogge 《Journal of Materials Engineering and Performance》2005,14(2):203-211
Transmutation of nuclear waste is currently being considered to transform long-lived isotopes to species with relatively short
half-lives and reduced radioactivity through capture and decay of minor actinides and fission products. This process is intended
for geologic disposal of spent nuclear fuels for shorter durations in the proposed Yucca Mountain repository. The molten lead-bismuth-eutectic
will be used as a target and coolant during transmutation, which will be contained in a subsystem vessel made from materials
such as austenitic (304L) and martensitic (EP-823 and HT-9) stainless steels. The structural materials used in this vessel
will be subjected to welding operations and plastic deformation during fabrication. The resultant residual stresses cannot
be totally eliminated even by stress-relief operations. Destructive and nondestructive techniques have been used to evaluate
residual stresses in the welded and cold-worked specimens. Results indicate that tensile residual stresses were generated
at the fusion line of the welded specimens made from either austenitic or martensitic stainless steel, with reduced stresses
away from this region. The magnitude of residual stress in the cold-worked specimens was enhanced at intermediate cold-reduction
levels, showing tensile residual stresses in the austenitic material while exhibiting compressive stresses in the martensitic
alloys. Comparative analyses of the resultant data obtained by different techniques revealed consistent stress patterns. 相似文献
19.
20.
采用铜填充金属对Ti-15-3钛合金与304不锈钢进行电子束焊接,对Ti/Fe和Ti/Cu/Fe接头在焊接过程中的温度场和应力场进行数值模拟和试验测量。结果表明,高斯旋转体热源适用于电子束焊接过程的模拟。温度场对于焊缝中心呈非对称分布,钛侧的温度高于不锈钢侧的。热应力同样呈非对称分布,残余拉应力主要存在于不锈钢侧。铜填充金属的加入,降低了焊接过程中的峰值温度、温度梯度以及残余应力,纵向和横向残余拉应力分别降低了66MPa和31MPa。从温度场和应力场的角度可以看出,铜合金是一种较好的Ti-15-3钛合金与304不锈钢电子束焊接的填充金属材料。 相似文献