焊接热输入对X100管线钢粗晶区组织及性能的影响

第31卷第3期2010年3月焊 接 学 报TRANSACTI ONS OF T HE C H I N A W ELDI NG I N STI TUTI ONVo.l 31 No .3M arch2010收稿日期:2009-04-09基金项目:国家自然科学基金资助项目(50874090)焊接热输入对X100管线钢粗晶区组织及性能的影响张骁勇1,2, 高惠临2, 庄传晶3, 吉玲康3(1.西安建筑科技大学材料科学与工程学院,西安 710048;2.西安石油大学材料科学与工程学院,西安 710065;3.中国石油天然气集团公司管材研究所,西安 710065)摘 要:采用热模拟技术、显微分析方法和力学性能测试等手段,对X100管线钢在不同焊接热输入下粗晶区的组织及性能的变化规律进行了研究.结果表明,随着焊接热输入的增加,X100管线钢的强韧性降低.当热输入为10kJ/c m 左右时,焊接粗晶热影响区的显微组织以贝氏体铁素体和粒状贝氏体为主,这种组织赋予材料以最佳的强韧性水平;当热输入为20kJ/c m 左右时,焊接粗晶热影响区的显微组织以粒状贝氏体和准多边形铁素体为主,材料有较好的强韧配合;而当热输入大于30kJ/c m 时,由于多边形铁素体增多,材料的强韧性降低.因此可将10~20kJ/c m 作为X 100管线钢的推荐热输入.关键词:X100管线钢;焊接热输入;组织;性能中图分类号:TG 142.1文献标识码:A文章编号:0253-360X (2010)03-0029-04张骁勇0 序 言X100是超高强度管线钢中的一种典型钢种.采用X100作为高压、大流量天然气输送管线管材,具有较大的经济效益.资料显示[1,2],在油气管道建设中,采用X80代替X70,可降低成本7%;采用X100代替X70,则可降低成本30%.所以X100管线钢的研究和开发,日益受到人们的关注.X100是一种新型的微合金化管线钢,在国内外的研究历史不长.在已有的文献中[3-5],多限于管线钢钢板性能的研究,对X100管线钢在焊接热过程中组织及性能的特征及其变化规律却知之不多.焊接热影响区粗晶区是整个焊接接头中性能最为薄弱的区域,因此研究X100管线钢在不同焊接热输入条件下的粗晶区组织及性能的变化规律及其焊接脆化的特征,对掌握X100管线钢焊接冶金的基本规律和推动X100管线钢的工业应用具有重要的意义.1 试验方法试验用X100管线钢板厚度为14.3mm,化学成分见表1,力学性能见表2,其基本金相组织为针状铁素体.表1 X100的化学成分(质量分数,%)Tab l e 1 C hem i c a l composition o f X100p ipe li n e s t ee lC S i M n P S C r M o 0.050.252.000.0120.00320.330.33N i Nb V T i Cu A l Fe 0.460.0550.0070.0220.200.046余量表2 X100的常规力学性能Tab l e 2 Mechan ica l p roper ties o f X100p ipe li n e st ee l屈服强度R e L /M Pa 抗拉强度R m /M Pa 断后伸长率A (%)屈强比R eL /R m 冲击吸收功A KV /J 73080520.50.91191采用热模拟试验获取X100管线钢在不同焊接热输入条件下粗晶热影响区(coarse gra i n hea t affect zone ,CGHAZ)的组织结构.热模拟试验在G leeble 1500型热模拟机上进行,热模拟参数如表3所示.其中热循环的几种t 8/5覆盖了石油、天然气输送钢管在制管焊接和野外施工焊接过程中所采用的不同焊接热输入下的冷却参数.热模拟试样分别采用 10mm 65mm 和10.5mm 10.5mm 55mm 的初始试样,试样于板厚中部(沿板厚方向两面对称加工)横向截取.热模拟试验后再将试样加工 5mm 25mm 的标准比例拉伸试样和10mm 10mm 55mm 的标准Charpy 冲击试样,沿板厚方向开制V 形缺口.拉伸试验在30焊 接 学 报第31卷表3 X100焊接粗晶影响区热模拟参数Tab l e 3 Ther m a l sm i u la tion parame ters for CGHA Z热输入E /(kJ c m -1)加热速度v /(! s -1)峰值温度T /!冷却时间t 8/5/s 高温停留时间t H /s900!1100!10130130053.622.95151301300105.433.602013013002010.867.203013013004021.7114.414013013007038.0025.2350130130010054.2836.03MTS ∀880型万能试验机上进行;冲击试验在JBC -300电子测力冲击试验机上进行.光学金相试样经机械抛光后以3%硝酸酒精溶液进行腐蚀,在REC HART MEF3A 光学显微镜下观察.TE M 试样经机械减薄至50 m 后,在双喷电解装置上以10%高氯酸+90%醋酸溶液进行双喷,在JE M 200CX 透射电子显微镜上观察.SE M 试验在TESLA ∀BS ∀300型扫描电子显微镜上进行.2 试验结果及分析2.1 力学性能特征2.1.1 强塑性X100焊接粗晶热影响区的强塑性与焊接热输入的关系如图1所示.从图中可以看出,随着热输入的增加,屈服强度和抗拉强度降低,断后伸长率略有变化.在低的焊接热输入条件下可获得高的强度水平.图1 X100在不同热输入下的拉伸力学性能F i g 1 Tensile m echan i c a l p rope rty o f X100a t d ifferen thea t inpu t s2.1.2 冲击吸收功在不同焊接热输入条件下,X100焊接粗晶热影响区在-20!时的夏比冲击吸收功变化规律如图2所示.图2 X100在不同热输入下的冲击吸收功(-20!)Fig 2Im pact abso rp tion energy o f X100a t d iff erent hea t inpu ts(-20!)试验结果表明,X100CGHAZ 的冲击吸收功随着热输入的增加而降低.当热输入在10~20kJ/c m 范围内,CGHAZ 的韧性符合工程要求.当热输入超过20kJ/c m 时,CGHAZ 的韧性明显降低,表现为焊接局部脆化.为了研究X100CGHAZ 的韧脆转变能力,测试了X100CGHAZ 在热输入为10kJ/c m 下的系列温度冲击吸收功.试验结果如图3所示.试验结果表明,在不同的试验温度下,焊接粗晶热影响区的韧性变化不大,具有优良的韧脆转变能力.图3 E =10kJ/c m 时CGHAZ 系列冲击吸收功Fig 3 I mpact abso rp tion ene rgy a t ser i a l t empe ra ture a tE =10kJ /cm2.2 组织结构特征及其对性能的影响现代管线钢是一种控轧、控冷状态的低碳微合金化钢.由于低碳、超低碳和多元的微合金化设计,以及在焊接过程中加热速度快、加热温度高和冷却速度范围较广的工艺特点,管线钢焊接粗晶热影响区(CGHAZ)的显微组织形态呈现多样性和复杂性[6].X100管线钢母材典型的光学显微组织为针状铁素体.在TE M 下,这种针状铁素体的形态如图4,第3期张骁勇,等:焊接热输入对X100管线钢粗晶区组织及性能的影响31由平行的板条贝氏体铁素体组成,板条间分布有M A 组元.图4 X100母材的透射电镜组织Fig 4 TEM m icrostructure o f X100base stee l具有针状铁素体特征的这种X100管线钢在经受不同焊接参数的热过程后,其显微组织发生较大的变化.图5是在不同的焊接热输入下,X100焊接粗晶热影响区的光学显微组织.已有的研究结果表明[7],在管线钢的焊接热过程中,根据焊接热输入不同,所形成的主要组织形态主要有多边形铁素体(PF)、准多边形铁素体(QF)、粒状贝氏体(GB )和贝氏体铁素体(BF).图5a 表明,在较低的焊接热输入下(10kJ/c m ),由于冷却速度较大,CGHAZ 的组织形态多为从奥氏体晶界向晶内平行生长的细密板条,不同位向的板条使原奥氏体晶界清晰可见.分析表明,这种细密的板条组织为BF+GB,板条间为薄膜状图5 X100在不同焊接热输入下的光学显微组织F ig 5 OM m icrostruct u re o f X100a t d iff e ren twe l d ing inp uts或条状M A,组织较为细小.这种BF+GB 的SE M 和TE M 的电子显微形态如图6所示.这一组织形态所具有的细小的有效晶粒、高密度的位错亚结构和弥散分布的微合金碳、氮化合物的沉淀析出等组织结构因素,赋予材料优良的强韧特性[8].在中等焊接热输入下(20kJ/c m ),管线钢C GH图6 E =10kJ/cm 时的组织F ig 6 M icrostruc t u rea l at E =10kJ /cmAZ 组织形态有所不同.由图5b 可以看出,由于冷速有所降低,C GHAZ 的组织主要为GB +QF .这种组织形态的SE M 形貌如图7所示.比较图6和图7可以发现,在图6的快冷条件下,板条细小,板条间的岛状组织纵横比较大,并由这种岛状组织勾画出板条的痕迹.而在图7的较慢冷却速度下,这种岛状组织多呈块状,并出现部分QF ,因而使得CGHAZ 的强韧性有所降低.32 焊 接 学 报第31卷图7 E =20kJ/c m 时的扫描电镜形貌Fig 7 SEM mo rpho l o gy a t E =20kJ /cm在高的焊接热输入下(50kJ/c m ),由于冷却速度的降低,管线钢的组织形态发生了明显的变化.由图5c 的组织观察可以发现:一方面,晶粒粗化的倾向比较明显;另一方面,组织中的QF+PF 增多.在TE M 下(图8),这种多边形铁素体或等轴铁素体的组织特征揭示得更为清晰.一般认为[7],多边形铁素体不是管线钢的理想组织状态.随着多边形铁素体或等轴铁素体组织含量的增加,材料的强韧性降低.图8 E =50kJ/c m 时形成的多边形铁素体F i g 8 PF a t E =50kJ /c m3 结 论(1)随着焊接热输入的增加,X100管线钢的强韧性降低.当焊接热输入在10~20kJ/c m 范围内,X100管线钢的焊接粗晶热影响区有较好的强韧特性,可作为X100管线钢推荐的热输入.(2)在10kJ/c m 左右的较低热输入下,X100管线钢焊接粗晶热影响区的显微组织为BF+GB .这种组织赋予材料以最佳的强韧性水平.(3)在20kJ/c m 左右的中等焊接热输入下,X100管线钢焊接粗晶热影响区的显微组织以GB+QF 为主,材料有较好的强韧配合.(4)当热输入为50kJ/c m 时,一方面晶粒粗化比较明显,另一方面粗晶区中的BF 和GB 被QF 和PF 替代,致使材料的强韧性降低.参考文献:[1] Okaguch iS.P roduction and devel op m en t ofX100and X120gradeli ne p i p es [C ]#B eiji ng :Internati onal S e m inar Forum of X100/X120Grate H igh Perf or m ance P i pe Steels ,2005.[2] 罗海文,董 瀚.高级别管线钢X80-X120的研发与应用[J].中国冶金,2006,16(4):14-15.Luo H ai w en,DongH an .Devel opm en t of X80-X120h i gh grade li nep i p e steels and t h ei r app li cati on s [J ].Ch i na M etallurgy ,2006,16(4):14-15.[3] G l overA.Research and app licati on ofX100and X120[C ]#B eiji ng :Proceed i ngs of Sy m pos i um on X80Grade S teel and Line p i pes ,2004.[4] Tak euch i I .Devel opm ent and evaluati on of h i gh strengt h li nepipef or h i gh press u re gas trans mm i son p i peli ne[C ]#X i an:Interna ti on alS e m inar on App lication ofH igh Strengt h L i ne P i pe ,2006.[5] 郑 磊,傅俊岩.高等级管线钢的发展现状[J].钢铁,2006,41(10):1-10.Zheng Le,i Fu J unyan .Recen t devel opm en t of high p erf or m ance p i peli n e steel[J].Steel&Iron,2006,41(10):1-10.[6] 高惠临.管线钢∀∀∀组织性能焊接行为[M ].西安:陕西科学技术出版社,1995.[7] 冯耀荣,高惠临,霍春勇,等.管线钢显微组织的分析与鉴别[M ].西安:陕西科学技术出版社,2008.[8] 李鹤林,郭生武,冯耀荣,等.高强度微合金管线钢显微组织分析与鉴别图谱[M ].北京:石油工业出版社,2001.作者简介:张骁勇,男,1971年出生,博士研究生.主要从事管线钢的研究和教学工作.发表论文10余篇.Em ai :lxyzhang @MA I N TOPI C S,ABSTRACTS&KE Y WORDS2010,Vo.l31,N o.3Abstrac t:The effec ts of w elding speed and we l d i ng d irec ti on on N d:YAG l ase r s hort currentM AG hybri d we l d i ng stab ili ty were i nvestigated.The expe ri m en tal results sho w ed tha t we l d i ng arc stability o fM AG and laser+MAG wou l d decrease w ith the i ncreasi ng of w elding speed,but the a rc o f laser+M AG get m ore stab l e compar i ng w it h M AG arc.The max i m a l w e l d i ng speed o f laser+MAG is m ore than one ti m e fast comparing w ith tha t of MAG.The hybr i d w eldi ng arc i n arc l eading d irec ti on w ou l d get m ore stable co m pari ng w i th that o f lase r lead i ng d irec ti on.K ey word s: GM AW;laser w eldi ng;hyb ri d we ldi ng; w elding pro cess stabilityAnal ysis of laser M AG hybrid we l d i ng p las m a rad i ation L I Zhiyong1,W ANG W ei2,W ANG X uyou2,L I H uan3(1. W e l d i ng R esearch Cen ter,N orth U n i ve rs i ty of Ch i na,T aiyuan 100081,Ch i na;2.H arbin W elding Institute,H arb i n150080, Ch i na;3.Schoo l of M ate rial Sc i ence and Eng i neer i ng,T ian jin U n i versity,T ian jin300072,Ch i na).p21-24,28Abstrac t: H o llow probe i s used t o detect the p l as m a rad i a ti on o f specific po i nt pass i ng the probe for spectru m co llecti ng. T he rad i a ti on o fMAG and l ase r M AG hybrid we l d i ng are co llect ed w ith fi ber spectrom eter.The spa ti a l distr i buti on o f t he rad i a ti on is ana l yzed to compare the d ifferences bet w een w e l d i ng process w it h and w it hou t laser hybr i d.Further m ore,h i gh speed v ideo is a lso appli ed to study the coupli ng m echanics o f l aser M AG hybr i d.The res u lt sho w s t hat a h i ghe r radiati on i ntensity zone w ill be for m ed i n the arc center.Bes i de t he cen ter zone, there is a so m ewhat l owe r rad i a ti on i ntensity zone.An∃ion ized duct zone%w ill be f o r m ed near the lase r f o cused po i nt.T he ion ized duc t i s dom ina ted by F e fu m e.The ion ized duct m akes the w elding arc m ore stable w hen t he l aser is appli ed.The h i gher ra d i ation i n tensity zone changes the distr i bution o f plas m a energy, thus m akes t he energy f ocus on the arc center.The coupli ng e ffect of l aser MAG hybrid w eldi ng w ill f o r m w eld bead w it h dee per pene trati on than M AG w e l d i ng.K ey word s: laser;M AG;hybrid we l d i ng;plas ma;spec trumFeature evalua ti on and selection of pen etration arc sound si gna l based on n eural n et work L I U L ij un1,2,LAN H u2, ZHENG H ongyan3(1.N i ngbo Institute of T echno l ogy,Zhe ji ang U n i versity,N i ngbo315100,Zhe ji ang,Ch i na;2.Schoo l ofM a teria l Sc ience&Eng i neeri ng,H arb i n U niversity o f Science and T echnology,H a rbin150080,Chi na;3.A pplied Science Col leg e,H arb i n U n i versity of Sc i ence and T echno l ogy,H a rbin 150080,Ch i na).p25-28Abstrac t: In we l d i ng processi ng pene trati on detecti on and d i agnos i s based on arc sound,how t o choose its proper para m e ters is v i ta l t o diagnosis.The feature ev al uation and se l ec ti on m ethods w ere presented,t he resu lts tra i ned by neura l net w ork w ere used to eva l uate fea t ure param eters.Because neural net w ork sati sfied the non li near m app i ng requ i re m ent for high reso l u ti on i nfor m ation compression,the co m plex class ificati on proble m in w elding penetration pattern recogn iti on was transferred to fea t ure pro cessi ng stag e,and fea t ure extra tion w as rea lized by neu ra l net w ork effecti ve l y.An ill ustrati on vali dated t he e ffecti veness o f the m e t hod.K ey words: neural net w ork;penetrati on;arc sound;fea t u re eva l uati on;patte rn recognitionInfluence of w elding heat i npu t on m icrostructure and prop erties of coarse grai n h eat affected zon e i n X100p ipe li n e steel Z HANG X i aoyong1,2,GAO H u ilin2,Z HUANG Chuan ji ng3,JI L i ngkang3(1.Schoo l of M ater i a l s Science and Eng i neering,X i an U n i versity o f A rchitecture and T echno l ogy,X i an 710055,Ch i na;2.School o f M ater i a ls Science and Eng i nee r i ng,X i an Sh i you U n i versity,X i an710065,Ch i na;3.T ubu lar G oods R esearch Center o f China N ati onal P etro l eu m Corporati on, X i an710065,China).p29-32Abstract: The i nfl uence o fw e l d i ng heat i nput on t he m i crostructure character izati on and properties of coarse g ra i n heat affected zone(CGHA Z)i n a X100pi pe li ne stee l we re investi ga ted by m eans of t her m a l si m u lati on techn i que,m icroscopic ana l ys i s m ethod and m echan i ca l property testi ng.T he resu lts sho w ed tha t the streng th and toughness o f X100p i pe li ne stee l decreased w it h t he w e l d i ng hea t i npu t i ncreasi ng.T he m icro structure of CGHAZ was m a i nly m ade up o f bainitic ferrit and granular ba i n iti c w hich cou l d bring ex ce llent streng t h and toughness when w e l ding heat w as about10kJ/c m.The quasi po lygonal ferr i te and g ranu l ar bai n itic were for m ed w ith w eldi ng heat i nput about 20kJ/c m,w hich could g et fine streng t h toughness.W hen the w e l ding heat i nput w as higher than30kJ/c m,the streng t h and toughness decreased because of t he i ncreas i ng o f po l ygonal fe r rite.Therefore,w eldi ng hea t i nput at rang e o f10-20kJ/cm w as reco mm ended i n t he we ldi ng process of X100pipe li ne stee ls.K ey w ords: X100p i peli ne stee;l w e l d i ng hea t i nput;m i crostructure;propertiesE stab lish of u ltrason ic residual stress m easure m ent s ystem based on ent i re en ve l op e w eigh ti ng algorith m W U Zhong hua1,2,Z HANG Shipi ng3,S UN H aoyu2,Z HU Z heng3(1.Co l leg e ofM echanical and E lectron ic Eng i neeri ng,Chi na U n i ve rs i ty o f P etro l eu m,Dongy i ng257061,Shandong,China;2.D rilli ng T echno l ogy R esearch Institute,Sheng li P etro l eu m Adm i n istra ti on Bureau,D ongy i ng257017,Shandong,Ch i na;3.Schoo l o f E lectr ica l Eng i neer i ng and A utoma ti c,H a rb i n Institute o fT echno l ogy,H arb i n150001,China).p33-36Abstract: The entire enve l ope w e i ghti ng algor i th m is pro posed in th i s paper and rea lized by v irtual i nstru m ent to obtain res i dua l stress by ultrason i c m easure m ent.D ifferent we i ght of re ference po i nt i s assi gned to m easure ti m e of echo signa l m ore accura pared w ith trad i tiona l si ng l e t hreshold m ethod, the experi m ent results sho w tha t t he a lgo rith m i m proved t he sta b ili za ti on of repea t m easure m ent at t he sa m e po i nt by different cond iti ons.T he uncerta i nty is ca l culated to vali date t he accuracy o f the ultrasonic measure m ent.K ey words: u ltrason ic m easurem ent;we l d i ng resi dua l stress;w e i ghti ng algor it h mH igh grad ien t residua l stresses during l aser deep penetrat i on we l d i ng of titan i um a lloy ZHANG K e rong,Z HANG Jianx un(School of M ater ials Science&Eng i neer i ng,X i an Jiaotong&。