GH99镍基合金薄板电子束焊接头疲劳性能研究

电子束焊作为一种先进的连接技术,具有能量集中、焊接速度快、热影响区小等特点,被广泛应用于工业工程、航空航天等国民经济的重要领域。随着航天飞行器发动机设计寿命的不断提高,主要结构部件的电子束焊接头疲劳性能越来越受到设计工作者的关注,研究电子束焊接头的疲劳性能已经成为焊接工作者一个重要的课题。本文采用电子束焊接工艺,制备了GH99镍基高温合金薄板对接接头。针对电子束焊接头,进行了显微硬度测试、疲劳性能的研究及疲劳失效机理分析。研究表明,电子束焊接头焊缝中心及热影响区的维氏硬度与GH99镍基高温合金母材金属基本相同,接头并未出现性能的不均匀性。对两种工艺下的电子束焊接头的疲劳S-N曲线分析表明,适当加大电子束焊焊接电流,有利于减少焊缝焊根部位的焊接缺陷,有利于提高电子束焊接头的疲劳性能,从而提高了焊接接头疲劳寿命。

Study on Fatigue Property of Electron Beam Welded Joint of GH99 Nickel-based Alloy

Electron beam welding is an advanced welding technology,which has the characteristics of high energy density,fast welding speed and small heat-affected zone.The electron beam welding is widely used in industrial engineering,aerospace and other areas of the national economy.With the continuous improvement of design life of the spacecraft engine,the designers pay more and more attentions to the fatigue properties of electron beam welded joints of the main structural components.Research on the fatigue properties of electron beam welded joints has become an important issue for welding workers.Square butt joints of GH99nickel-base alloy sheet are fabricated using electron beam welding.The micro-hardness,fatigue properties and fatigue failure mechanism of the electron beam welded joints are tested and analyzed.It is found that the vickers hardness of weld center and heat affected zone of electron beam welded joints are basically the same as the GH99nickel-based superalloy base metal.The analysis of fatigue S-N curves in two kinds of electron beam welding process shows that the appropriate increase of electron beam welding current can reduce the welding defects of weldment,and improve the fatigue properties of electron beam welded joint and improve the fatigue life of welded joint.