Creep Behavior of Fusion Zone and Base Metal of the Electron Beam Weldments of a Near-alpha Titanium

来源 :Journal of Materials Science & Technology | 被引量 : 0次 | 上传用户:luye063006300630
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The high temperature creep behavior of fusion zone(FZ) and base metal(BM) of the electron beam weldments of a near-alpha titanium alloy Ti-60 has been investigated.While the BM shows a fully transformed,coarse primary β grains with large colonies consisting of aligned α lamellar,the FZ exhibits thin martensitic α platelets in the columnar β grains.The creep results show that the steady state creep rates of FZ follow the power-law creep,with the stress exponents obtained in the range from 5.6(550°C) to 5.9(600°C),and corrected activation energies of 309-352 kJ/mol;the stress exponents of BM exhibit different values when the creep testing stress and temperature alternate.The values of 2.4-3.2 are obtained when the stresses are under 220 MPa or the temperature is 550°C,also an exponent of 6.6 is achieved at stresses above 220 MPa at 600°C.The corrected activation energies of BM corresponding to the stress exponents are 123-161 kJ/mol(n=2.4-3.2) and 344 kJ/mol(n=6.6).The creep mechanisms of FZ and BM have been discussed in light of the creep microstructures,activation energies and the stress exponents.The creep mechanisms of FZ is the diffusion controlled dislocation climb,the creep of BM is controlled by ’solute drag’ creep and dislocation climb when the stress and temperature are different.Transmission electron microscopy(TEM) observations of the dislocation structures of crept specimens are presented to give some supports for the creep behavior of FZ and BM.In addition to the creep mechanism of dislocation movement,the interface sliding has been found to play an important role during creep of FZ. The high temperature creep behavior of fusion zone (FZ) and base metal (BM) of the electron beam weldments of a near-alpha titanium alloy Ti-60 has been investigated. Whilst the BM shows a fully transformed, coarse primary beta grains with large colonies consisting of aligned α lamellar, the FZ exhibits thin-plate martensitic α platelets in the columnar β-grains. The creep results show that the steady state creep rates of FZ follow the power-law creep, with the stress exponents obtained in the range from 5.6 ( 550 ° C) to 5.9 (600 ° C), and corrected activation energies of 309-352 kJ / mol; the stress exponents of BM exhibit different values ​​when the creep testing stress and temperature alternate. These values ​​of 2.4-3.2 are obtained when the stresses are under 220 MPa or the temperature is 550 ° C, also an exponent of 6.6 is achieved at at least 220 MPa at 600 ° C. The corrected activation energies of BM corresponding to the stress exponents are 123-161 kJ / mol ( n = 2.4-3.2) and 344 kJ / mol (n = 6.6) .The creep mech anisms of FZ and BM have been discussed in light of the creep microstructures, activation energies and the stress exponents. creep mechanisms of FZ is the diffusion controlled dislocation climb, the creep of BM is controlled by ’solute drag’ creep and dislocation climb when the stress and temperature are different. Transmission electron microscopy (TEM) observations of the dislocation structures of crept specimens are presented to give some supports for the creep behavior of FZ and BM. addition to the creep mechanism of dislocation movement, the interface sliding has been found to play an important role during creep of FZ.
其他文献
一、2011年三季度经济运行情况内蒙古(DRC)宏观景气预警指数显示,2011年3月以来,全区宏观经济预警指数逐步回调,全区经济在“正常区”保持平稳增长态势。8月份,宏观经济预警
讲述了液压AGC在轧钢工艺中的原理,SIEMENS TDC的特点及其软硬件功能,济钢中板厂在原来电动压下系统的基础上改造设计液压压下系统,整合粗轧、精轧两轧机压下系统,并详述了其
多功能框架式防电作业车是修建电气化铁道跨线桥安全施工的最新设备。此设备可在接触网不停电、列车正常通行的条件下进行下列各项工程的施工: ·跨线桥架梁施工。以往工地架
11月7日,中国与印尼合作兴建的棉兰-瓜拉纳姆高速公路在苏门答腊岛棉兰市Penara村举行开工典礼。据了解,该高速公路工程项目是由中国政府贷款,中国港湾工程有限责任公司、中