本文選題：雙金屬復(fù)合管 + 焊接接頭�。� 參考：《西南石油大學(xué)》2017年碩士論文

【摘要】：雙金屬復(fù)合管由于其突出的性價比,目前在油氣田建設(shè)及運輸方面應(yīng)用得越來越廣泛。但是復(fù)合管基層與覆層的化學(xué)成分以及物理性能差異較大,在進行管道的焊接連接時,過渡層焊縫屬于異種金屬的焊接,相比于同種金屬來說難度更大。尤其是機械式復(fù)合管,其基層和覆層之間存在一定縫隙,里面可能含有空氣、水分及其他夾雜物,在進行過渡層的焊接時容易導(dǎo)致層間出現(xiàn)氣孔、熔池塌陷形成焊瘤以及焊不透等一系列焊接缺陷。因此,本文針對機械式雙金屬復(fù)合管焊接問題,制定了三種不同的焊接方案,分別采用了 V型坡口、封焊坡口和堆焊坡口對X65/316L雙金屬復(fù)合管進行焊接,對獲得的焊接接頭分別進行了組織與成分分析、力學(xué)性能測試與腐蝕性能測試,根據(jù)試驗結(jié)果評價三種焊接接頭性能的好壞,從而判定三種焊接方案的設(shè)計是否合理。顯微組織觀察結(jié)果表明:三種焊接方案下的復(fù)合管焊接接頭焊縫組織均為鐵素體+奧氏體雙相組織,并且在Ni、Cr等元素含量高的地方出現(xiàn)了以胞狀晶、樹枝晶和等軸晶等不同方式生長的晶粒形態(tài)。過渡層焊縫物相分析表明:三種復(fù)合管焊接接頭過渡層焊縫的物相均由α+γ兩相組成,沒有發(fā)現(xiàn)σ相、M23C6相等有害相析出。熔合區(qū)元素線掃描分析表明:Ni、Cr、Mo等合金元素在該區(qū)域均產(chǎn)生了一定的濃度梯度,但是并未發(fā)生明顯的偏聚現(xiàn)象,C元素在V型坡口焊接接頭和封焊坡口焊接接頭中出現(xiàn)了輕微的擴散遷移現(xiàn)象。力學(xué)性能測試結(jié)果表明:V型坡口焊接接頭、封焊坡口焊接接頭和堆焊坡口焊接接頭的顯微硬度最大值分別為231HV、213HV、222HV,均小于酸性介質(zhì)下管線鋼的硬度極限值250HV,說明硬度方面三種焊接接頭均合格,其中焊縫區(qū)域的顯微硬度值均比熱影響區(qū)和母材區(qū)域要高。三種焊接接頭的屈服強度平均值分別為443.7MPa、462.3MPa、481.7MPa,其中V型坡口焊接接頭沒有達到復(fù)合管基層X65母材的最低屈服強度值448MPa,而另外兩種焊接接頭滿足要求。三種焊接接頭的平均沖擊韌度均達到X65碳鋼母材的使用要求,焊縫區(qū)域的沖擊韌度普遍比熱影響區(qū)的沖擊韌度要高。三種焊接接頭焊縫和熱影響區(qū)的沖擊斷口表現(xiàn)為大小和深度不等的等軸韌窩形貌,并且都伴有山脊?fàn)钏毫牙獯嬖?屬于典型的韌性斷裂機制。腐蝕性能測試結(jié)果表明:電化學(xué)測試結(jié)果和化學(xué)浸泡試驗結(jié)果比較一致,都表明了三種復(fù)合管焊接接頭具有較好的耐腐蝕性能,其中封焊坡口焊接接頭和堆焊坡口焊接接頭的耐腐蝕性能優(yōu)于316L不銹鋼母材,而V型坡口焊接接頭的耐腐蝕性能比316L母材要差。綜上所述,采用V型坡口進行復(fù)合管焊接的試驗方案不能滿足實際工程需要,而采用封焊坡口和堆焊坡口的焊接方案參數(shù)設(shè)計比較合理,滿足實際生產(chǎn)要求。
[Abstract]:Bimetallic composite pipe is widely used in oil and gas field construction and transportation due to its outstanding cost-performance ratio. However, the chemical composition and physical properties of the base layer and the cladding of composite pipe are quite different, so the welding seam of transition layer belongs to dissimilar metal, which is more difficult than that of the same metal. In particular, there is a gap between the base layer and the cladding of a mechanical composite pipe, which may contain air, moisture and other inclusions, which can easily lead to blooms between layers when welding the transition layer. Weld pool collapse forms a series of welding defects, such as welding nodule and welding failure. Therefore, in order to solve the welding problem of mechanical bimetallic composite pipe, three different welding schemes have been developed in this paper. The V groove, sealing groove and surfacing groove are used to weld X65p 316L bimetal composite pipe, respectively. The microstructure and composition of the welded joints were analyzed, the mechanical properties and corrosion properties of the welded joints were tested, and the performances of the three welded joints were evaluated according to the test results, so as to determine whether the design of the three welding schemes was reasonable or not. The results of microstructure observation show that the weld microstructure of welded joint of composite pipe under three kinds of welding schemes is ferrite austenitic dual phase structure, and the cellular crystal appears in the place where the content of nio Cr and other elements is high. Dendritic and equiaxed crystal growth in different ways of grain morphology. The phase analysis of transition layer weld shows that the phase of transition layer weld of three kinds of composite pipe welded joint is composed of 偽 緯 two-phase, and no 蟽 phase M23C6 is found to precipitate from the same harmful phase. The linear scanning analysis of the elements in the fusion region shows that there exists a certain concentration gradient in the fusion region. However, there is no obvious segregation phenomenon of C element in V-groove welded joint and seal weld groove welding joint, there is a slight diffusion migration phenomenon. The test results of mechanical properties show that: v groove welded joint, The maximum microhardness of seal welded groove joint and surfacing groove welding joint is 231HVP213HV222HVrespectively, which is less than the hardness limit value of pipeline steel in acid medium 250HV. it shows that the hardness of the three welded joints is up to standard. The microhardness of weld zone is higher than that of heat affected zone and base metal zone. The average yield strength of the three welded joints is 443.7 MPA / 462.3MPA / 481.7 MPa respectively. The V groove welded joint does not reach the minimum yield strength value of the base material X65 of the composite pipe, while the other two kinds of welded joints meet the requirements. The average impact toughness of the three welded joints is up to the requirements of the base metal of X65 carbon steel, and the impact toughness of the weld zone is generally higher than that of the heat-affected zone. The impact fracture of the weld and heat affected zone of the three kinds of welded joints shows the shape of equiaxed dimples with different sizes and depths, and all of them are accompanied by ridge-like tearing edges, which is a typical ductile fracture mechanism. The results of corrosion test show that the results of electrochemical test are consistent with those of chemical immersion test. The results show that the three kinds of welded joints of composite pipe have good corrosion resistance. The corrosion resistance of sealing and surfacing groove welded joints is better than that of 316L stainless steel base metal, but the corrosion resistance of V-groove welded joints is worse than that of 316L base metal. To sum up, the test scheme of using V-shaped groove to weld composite pipe can not meet the actual engineering needs, but the welding scheme parameters of sealing welding groove and surfacing groove are more reasonable and meet the actual production requirements.
【學(xué)位授予單位】：西南石油大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TG407

【參考文獻】

相關(guān)期刊論文 前10條

1 趙晨光;彭清華;馬宏偉;魯欣豫;曹軍;;雙金屬復(fù)合管焊接技術(shù)探討[J];焊管;2013年01期

2 I.Danaee;M.Niknejad Khomami;A.A.Attar;;Corrosion of AISI 4130 Steel Alloy under Hydrodynamic Condition in Ethylene Glycol+Water+NO_2~- Solution[J];Journal of Materials Science & Technology;2013年01期

3 張念濤;徐連勇;韓永典;劉永貞;;X65/316L耐蝕合金內(nèi)襯管焊接接頭CO_2腐蝕行為研究[J];焊管;2012年01期

4 朱世東;王棟;李廣山;魏斌;趙雪會;李發(fā)根;;油氣田用雙金屬復(fù)合管研究現(xiàn)狀[J];腐蝕科學(xué)與防護技術(shù);2011年06期

5 郜玉新;;油氣田新型復(fù)合管道的開發(fā)研究[J];管道技術(shù)與設(shè)備;2011年04期

6 李發(fā)根;魏斌;邵曉東;蔡銳;;雙金屬復(fù)合管技術(shù)經(jīng)濟性分析[J];腐蝕科學(xué)與防護技術(shù);2011年01期

7 許愛華;院振剛;楊光;張靖;張鯤鵬;朱力揮;;雙金屬復(fù)合管的施工焊接技術(shù)[J];天然氣與石油;2010年06期

8 李發(fā)根;魏斌;邵曉東;蔡銳;;高腐蝕性油氣田用雙金屬復(fù)合管[J];油氣儲運;2010年05期

9 徐志友;;不銹鋼襯層雙金屬復(fù)合管的焊接[J];裝備制造;2010年04期

10 郭崇曉;張燕飛;吳澤;;雙金屬復(fù)合管在強腐蝕油氣田環(huán)境下的應(yīng)用分析及其在國內(nèi)的發(fā)展[J];全面腐蝕控制;2010年02期

相關(guān)會議論文 前1條

1 宋亞峰;;油氣田開采用冶金復(fù)合雙金屬復(fù)合管開發(fā)與應(yīng)用[A];2008雙（多）金屬復(fù)合管/板材生產(chǎn)技術(shù)開發(fā)與應(yīng)用學(xué)術(shù)研討會文集[C];2008年

相關(guān)博士學(xué)位論文 前1條

1 范兆廷;新型輸油氣雙金屬復(fù)合管道腐蝕及可靠性研究[D];重慶大學(xué);2013年

相關(guān)碩士學(xué)位論文 前3條

1 周京;Inconel601H鎳基合金焊縫化學(xué)法晶粒細化的研究[D];河北工業(yè)大學(xué);2015年

2 孫育祿;耐蝕合金雙金屬復(fù)合管的應(yīng)用技術(shù)[D];西安石油大學(xué);2013年

3 陳忱;不銹鋼/碳鋼復(fù)合板的焊接工藝及接頭組織性能研究[D];南京航空航天大學(xué);2012年

，

本文編號：2075649