长期高温时效对有碳迁移发生的焊接接头的影响

发布时间：2018-03-06 19:10

本文选题：%Cr含B钢　切入点：高温时效　出处：《清华大学学报(自然科学版)》2015年10期 　论文类型：期刊论文

【摘要】：该文以采用9%Cr含B铁素体耐热钢为母材、2.25%Cr为填充金属的接头为对象,研究了高温时效过程对接头中的碳迁移层及其附近区域的影响。研究发现:经高温时效后,接头富碳区中的析出物发生粗化且数量增多,而贫碳区中析出物变化不大,导致贫/富碳层的硬度差异增大。有限元计算结果表明:在接头受载情况下,贫碳区会成为首先破坏的部位,并且高温时效会加剧这种破坏。透射电镜(TEM)结果表明:9%Cr含B钢热影响区(HAZ)中的晶界析出物在时效后粗化不明显,而晶内析出物则发生了明显的粗化,这主要是由于B在晶界聚集并通过占据析出物周围的空位阻碍了析出物粗化。
[Abstract]:In this paper, the effects of high temperature aging process on the carbon transfer layer and its adjacent region in the joints were studied by using 9Cr ferrite heat-resistant steel as the base material and 2.25Cr as the filler metal. The results show that: after high temperature aging, the effect of aging on the carbon transfer layer and its adjacent region in the joints is studied. The amount of precipitates in the carbon-rich zone of the joints is coarser and the amount of the precipitates increases, while the precipitates in the carbon-rich regions do not change much, which results in the increase of the hardness differences of the poor / carbon-rich layers. The results of finite element analysis show that: under the loading condition of the joints, The results of transmission electron microscopy (TEM) show that the grain boundary precipitates in the heat affected zone (HAZZ) of the weight 9Cr steel containing B are not coarsened obviously after aging. However, the coarsening of the precipitates occurred in the crystal, which was mainly due to the accumulation of B in the grain boundaries and the hindering of the coarsening of the precipitates by occupying the vacancies around the precipitates.
【作者单位】：清华大学机械工程系;
【基金】：上海市科学技术委员会资助项目(13DZ1101504)
【分类号】：TG407;TG156.92

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