天津大学学报
天津大學學報
천진대학학보
JOURNAL OF TIANJIN UNIVERSITY SCIENCE AND TECHNOLOGY
2013年
5期
453-457
,共5页
王颖%宋宗贤%王东坡%邓彩艳%赵小辉%刘亚骄
王穎%宋宗賢%王東坡%鄧綵豔%趙小輝%劉亞驕
왕영%송종현%왕동파%산채염%조소휘%류아교
无余高焊接接头%超声疲劳试验%鱼眼
無餘高銲接接頭%超聲疲勞試驗%魚眼
무여고한접접두%초성피로시험%어안
butt welds ground flush%ultrasonic fatigue test%fish-eye
采用自行研制的TJU-HJ-I型超声疲劳试验装置对EH36钢无余高焊接接头在超长寿命区间的疲劳性能进行研究.试验结果表明:在107循环周次以后试件仍然会在焊接接头发生断裂,并且 S-N 曲线仍呈下降趋势,没有出现传统意义上的疲劳极限.尽管不存在余高,焊接接头表面不存在应力集中,但是大部分试件仍然在焊接接头处断裂.通过扫描电子显微镜分析断口可以观察到,裂纹源大部分处于表面机械加工微痕及次表面微观缺陷处.另外,焊接接头中缺陷引起的“鱼眼”与母材中的“鱼眼”并不完全相同,前者的鱼眼中不存在视觉黑暗区.
採用自行研製的TJU-HJ-I型超聲疲勞試驗裝置對EH36鋼無餘高銲接接頭在超長壽命區間的疲勞性能進行研究.試驗結果錶明:在107循環週次以後試件仍然會在銲接接頭髮生斷裂,併且 S-N 麯線仍呈下降趨勢,沒有齣現傳統意義上的疲勞極限.儘管不存在餘高,銲接接頭錶麵不存在應力集中,但是大部分試件仍然在銲接接頭處斷裂.通過掃描電子顯微鏡分析斷口可以觀察到,裂紋源大部分處于錶麵機械加工微痕及次錶麵微觀缺陷處.另外,銲接接頭中缺陷引起的“魚眼”與母材中的“魚眼”併不完全相同,前者的魚眼中不存在視覺黑暗區.
채용자행연제적TJU-HJ-I형초성피로시험장치대EH36강무여고한접접두재초장수명구간적피로성능진행연구.시험결과표명:재107순배주차이후시건잉연회재한접접두발생단렬,병차 S-N 곡선잉정하강추세,몰유출현전통의의상적피로겁한.진관불존재여고,한접접두표면불존재응력집중,단시대부분시건잉연재한접접두처단렬.통과소묘전자현미경분석단구가이관찰도,렬문원대부분처우표면궤계가공미흔급차표면미관결함처.령외,한접접두중결함인기적“어안”여모재중적“어안”병불완전상동,전자적어안중불존재시각흑암구.
The super-long life fatigue properties of EH36 steel butt welds ground flush were studied by the self-made TJU-HJ-I type ultrasonic fatigue test device. Fatigue test results show that fracture still occurs in the welded joint after 107 cycles,and that the S-N curve descends continuously. There is no such fatigue limit as described by the traditional fatigue conception. Although welding residual height does not exist and stress concentration does not exist on welded joint surface,fracture still occurs in the joint. Scanning electron microscope(SEM)analysis shows that fatigue crack mostly initiates from machining micro mark and microstructure defects in subsurface. Besides,the“fish-eye”induced by the defects in welded joint is not all the same as that in the base steel. The optical dark area(ODA)does not exist in the former“fish-eye”.