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ID:5379371
大小:1.92 MB
页数:7页
时间:2017-12-08
《低合金高强 钢焊接构件在高温锅炉水中的应力腐蚀开裂行为研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、低合金高强钢焊接构件在高温锅炉水中的应力腐蚀开裂行为研究吴运祥(中国石化上海石油化工股份有限公司,上海200540)摘要:分析了某公司的2乙二醇R一120环氧乙烷反应器中c一11环焊缝开裂原因。对开裂c一11环焊缝开展了化学成分、金相观察、硬度测试、断口微观观察、EDS能谱分析等试验研究。试验发现:壳程、管板母材和焊缝金属化学成分分别满足SA543TypeBCL.1,SA508Gr.4NCL.1和MGS80的要求;从内壁管板侧热影响区起裂的主裂纹穿晶扩展,裂纹尖端沿晶扩展并有分叉,具有应力腐蚀裂纹特征;内壁附近焊缝两侧热影响区局部有马氏体组织;管板侧热影响区硬度最高为466.3HV10
2、;断口观察发现裂纹在内壁产生,是多源裂纹,沿壁厚向外壁扩展15mm,断口上有冰糖状等轴晶和柱状晶;裂纹断口探测到P和Na元素。该反应器开裂原因是由于焊接导致在管板与壳程焊接区域存在较高的残余应力,在高温锅炉水介质中,发生了应力腐蚀开裂,由内壁向外扩展,最终导致泄漏。关键词:ASMESA543TypeBCL.1;ASMESA508Gr.4NCL.1;焊接接头;应力腐蚀开裂中图分类号:TG142.33;TG172.9文献标识码:A文章编号:1001—4837(2010)06—0001—06doi:10.3969/j.issn.1001—4837.2010.06.001Investigati
3、ononStressCorrosionCrackingBehaviorofWeldJointofLowAlloySteelswithHighStrengthinHighTemperatureBoilerFeedWaterWUYun—xiang(SINOPECShanghaiPetrochemicalCompanyLimited,Shanghai200540,China)Abstract:Thereasonofleakofweldjoint(C一11)ofEOreactorofacompanywasanalyzedexperimen—tally.Theweldjoint(C一11)was
4、investigatedbyopticalemissionspectrometry,opticalmicroscopy,hardnesstester,scanningelectronmicroscopyequippedwithenergy—dispersiveX—rayspectroscopy.Itshowedthatthechemicalcompositionofshellplate,tubesheetandweldisconsistentwithspecificationofSA543TypeBCL.1,SA508Gr.4NCL.1,andMGS80,respectively.Th
5、etransgranularcrackinitiatedfromtheHAZoftubesheetsidenearinnersurfacepropagatedoutwards,andthecracktipswiththeirbrachesexpandedalongthecrystalline,whichhasthestresscorrosioncrackcharacteristic.Themartens—iteorganizationWaSobservedintheHAZneartheinnersurface.ThehighesthardnessintheHAZadja-centtot
6、ubesheetis466.3HV10.Thefractureobservationshowedthatcrackisthemultiplesourcecracks,expands15millalongwallthicknessoutwards,andequiaxedandcolumnarcrystalswerefoundonthefracture.TheelementsofPandNaweredetectedonthefracturesurface.Itcanbededucedthatthestresscorosioncrackinginhightemperaturewaterocc
7、uredbecauseofhighweldingresidualstresses,theleakofweldjoint(C一11)ofEOreactortookplaceeventually..1.低合金高强钢焊接构件在高温锅炉水中的应力腐蚀开裂行为研究VoW7.No62010Keywords:ASMESA543TypeBCL.1;ASMESA508Gr.4NCL.1;weldjoint;stresscorrosioncrack·ing壳程设计
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