Nimonic 80A合金螺栓的组织织构及高温应力松弛行为  

Texture characteristics and high temperature stress relaxation behaviors of Nimonic 80A alloy bolt

作　　者：麻建中 黄一君 黄友桥 汪博 张宁[4] 孟利[4] MA Jian-zhong;HUANG Yi-jun;HUANG You-qiao;WANG Bo;ZHANG Ning;MENG Li(Zhejiang Zheneng Lanxi Electric Power Generation Co.,Ltd.,Jinhua 321199,Zhejiang,China;Material Technology Department,Zhejiang Zheneng Technology Research Institute Co.,Ltd.,Hangzhou 311121,Zhejiang,China;Equipment Management Department,Zhejiang Zheneng Lanxi Electric Power Generation Co.,Ltd.,Jinhua 321199,Zhejiang,China;Metallurgical Technology Institute,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]浙江浙能兰溪发电有限责任公司,浙江金华321199 [2]浙江浙能技术研究院有限公司材料技术所,浙江杭州311121 [3]浙江浙能兰溪发电有限责任公司设备管理部,浙江金华321199 [4]钢铁研究总院有限公司冶金工艺研究所,北京100081

出　　处：《中国冶金》2022年第7期74-79,共6页China Metallurgy

基　　金：浙能集团科技项目(ZNKJ-2019-026)。

摘　　要：利用SEM与EBSD技术研究Nimonic 80A高温合金螺栓的组织织构特点,并对不同温度下的高温应力松弛行为及组织织构演变进行分析。结果表明,合金中γ相组织未形成显著织构,晶粒取向择尤情况与晶粒尺寸无对应性。合金中第二相主要为γ′相与Cr的碳化物,γ′相在基体中弥散分布,而Cr的碳化物分别在晶界析出和沿螺栓轴向“链状”分布,其分布特征与γ晶粒组织及取向无显著关联性。应力松弛前后,晶粒组织、碳化物分布及织构均无明显变化,但γ′相发生了一定的粗化。载荷一定时,温度对应力松弛行为存在显著影响,即较高温度下样品的应力松弛率较高。较高温度下位错滑移更易开动,与样品中更多晶粒表现出较高晶粒取向散布(GOS)值相对应,但各晶粒GOS值的高低未表现出晶粒取向与晶粒尺寸依赖性。The microstructure and texture characteristics of Nimonic 80A superalloy bolt were studied using SEM and EBSD techniques,meanwhile,stress relaxation behaviors at different high temperatures and the corresponding microstructure as well as texture evolution were analyzed.The results showed that no strong texture was obtained inγphase,and no correspondence was shown betweenγgrain orientation and grain size.γ′phase and Cr carbides were the main second phase in the alloy.Theγ′phase was dispersed in the matrix,while Cr carbides precipitated at grain boundaries and showed“chain”distribution along axial direction of the bolt respectively.The distribution characteristics of Cr carbides had no significant correlation withγgrain structure and orientation.Before and after stress relaxation experiments,microstructure,texture as well as the distribution of chromium carbide showed not change apparently,whileγ′phases were shown to coarsen.Under the same load,the experimental temperature influenced the stress relaxation behaviors,the higher temperature contributed to higher stress relaxation ratio,which could be related with easier dislocation slip.The phenomenon was consistent with more grains showing higher GOS(Grain Orientation Spread)values in the sample,while GOS value of individual grain did not show dependence on grain size and crystal orientation.

关 键 词：Nimonic 80A高温合金 高温应力松弛 组织 晶粒尺寸 晶粒取向 织构 

分 类 号：TG132.3[一般工业技术—材料科学与工程]