本文選題：壓力容器　切入點：異種鋼焊縫　出處：《東南大學》2015年碩士論文　論文類型：學位論文

【摘要】：核能是世界公認的安全、經(jīng)濟、清潔能源,許多國家都將發(fā)展核能作為本國能源計劃的重點。核能的堆型和容量有很多種,且在不斷地發(fā)展和完善,目前世界上裝機容量最多的是輕水壓水反應(yīng)堆(PWR)。輕水壓水堆核電站一回路包括反應(yīng)堆壓力容器、穩(wěn)壓器、蒸汽發(fā)生器、主泵、主管道等,壓力容器的異種鋼之間焊接所產(chǎn)生的焊縫性能如何,將直接影響到核電的安全性。本文研究了核電壓力容器異種鋼焊縫的性能及其薄弱環(huán)節(jié),通過超聲仿真檢測技術(shù)模擬了缺陷的形狀、分布、位置和超聲檢測參數(shù),采用核電現(xiàn)場多通道雙晶縱波聚焦超聲檢查技術(shù)對仿真結(jié)果進行了驗證。針對異種鋼焊縫,開展了焊縫成分、組織和性能研究,分析了斷口微觀形貌,并研究了焊縫融合線處的合金元素遷移率等,從而為探尋壓力容器異種鋼焊縫可能存在的薄弱環(huán)節(jié)提供實驗依據(jù)。研究結(jié)果表明,壓力容器異種鋼焊縫低合金鋼側(cè)熱影響區(qū)存在明顯的粗晶區(qū)和細晶區(qū),細晶區(qū)顯微硬度相對于母材增加了17%左右；熱影響區(qū)沖擊值波動較大,沖擊性能不穩(wěn)定,脆化和裂紋傾向較高,拉伸試樣全部斷于該部位；同時由于低合金鋼強度級別明顯低于奧氏體不銹鋼,判斷低合金鋼側(cè)熱影響區(qū)是整個異種鋼接頭性能的薄弱環(huán)節(jié)。根據(jù)異種鋼焊縫性能研究結(jié)果,利用CIVA超聲仿真軟件在壓力容器異種鋼焊縫低合金鋼側(cè)熔合線粗晶區(qū)域構(gòu)建超聲仿真模擬裂紋,模擬裂紋基本特征為：30mm×10mm矩形,方向與焊縫熔合線相平行,距工件內(nèi)表面的深度為9mm。超聲仿真研究結(jié)果表明,針對構(gòu)建的模擬裂紋,采用1.5MHz、70°TRL FS20超聲探頭檢測時缺陷響應(yīng)幅值最大,檢測效果最好。在超聲仿真試驗結(jié)果基礎(chǔ)上,本文選擇了4個1.5MHz、70°TRL FS20雙晶縱波聚焦斜探頭,輔以4個1.5MHz、45°TRL FS20雙晶縱波聚焦斜探頭和1個2MHz單晶縱波直探頭,從不同方向?qū)Τ曉噳K進行了驗證性掃查。1.5MHz、70°TRL FS20探頭掃查深度范圍為距RPV試塊內(nèi)表面0～13mm,1.5MHz、45°TRL FS20探頭掃查深度范圍為距試塊內(nèi)表面3-23mm,覆蓋了超聲仿真裂紋模擬區(qū)域。超聲檢查結(jié)果：選取帶缺陷的試塊進行驗證性超聲掃查,發(fā)現(xiàn)試塊內(nèi)表面存在三處缺陷,缺陷長、高分別為20.5mm、7.4mm,27.5mm、13.1mm,38.4mm、15.4mm;本課題RPV超聲試塊焊縫及兩側(cè)熱影響區(qū)無可記錄缺陷,表明該試塊既無仿真預(yù)估的裂紋,也無氣孔、夾雜等其它缺陷存在。根據(jù)試驗研究結(jié)果,本論文探討了壓力容器異種鋼焊縫服役環(huán)境和性能劣變機理,晶粒尺寸對超聲波檢查的影響,仿真技術(shù)與超聲波檢測的關(guān)系,以及壓力容器異種鋼焊縫超聲波檢測參數(shù)的優(yōu)化等。
[Abstract]:Nuclear energy is recognized as a safe, economic and clean energy source in the world. Many countries have made the development of nuclear energy the focus of their energy plans. There are many types and capacities of nuclear energy, and they are constantly developing and improving. At present, the largest installed capacity in the world is the light water pressure water reactor (LWPRR). The primary circuit of the LPWR nuclear power station includes reactor pressure vessels, regulators, steam generators, main pumps, main pipes, etc. The safety of nuclear power is directly affected by the weldability of dissimilar steel welded between different kinds of steel in pressure vessel. This paper studies the performance and weak link of the welding seam of dissimilar steel in nuclear pressure vessel. The shape, distribution, location and ultrasonic parameters of defects were simulated by ultrasonic simulation technique. The simulation results were verified by using multi-channel dual-crystal longitudinal wave focused ultrasonic inspection technique in nuclear power field. The composition, microstructure and properties of the weld were studied, the micromorphology of the fracture surface was analyzed, and the mobility of alloying elements at the fusion line of the weld was studied. The results show that there are obvious coarse-grained and fine-grained areas in the heat-affected zone of the low alloy steel weld of the dissimilar steel weld of pressure vessel. The microhardness of fine-grained zone increases by about 17% compared with the base metal, the impact value of the heat-affected zone fluctuates greatly, the impact property is unstable, the tendency of embrittlement and crack is higher, and the tensile specimens are all broken in this part. At the same time, because the strength grade of low alloy steel is obviously lower than that of austenitic stainless steel, judging the side heat affected zone of low alloy steel is the weak link of the whole dissimilar steel joint performance. The ultrasonic simulation crack was constructed by using CIVA software in the coarse grain region of the low alloy steel side fusion line of the dissimilar steel weld of pressure vessel. The basic characteristic of the simulated crack was: 1: 30mm 脳 10mm rectangle, and the direction was parallel to the weld seam fusion line. The depth from the inner surface of the workpiece is 9 mm. The results of ultrasonic simulation show that the defect response amplitude is the largest and the detection effect is the best when using 1.5 MHz TRL FS20 ultrasonic probe to detect the simulated crack. Based on the results of ultrasonic simulation test, In this paper, four 1.5 MHz FS20 70 擄TRL FS20 double crystal longitudinal wave focusing oblique probes, four 1.5 MHz TRL 45 擄TRL FS20 double crystal longitudinal wave focusing oblique probes and one 2MHz single crystal longitudinal wave straight probe are selected. The scanning depth range of 70 擄TRL FS20 probe is 0.13mm from the inner surface of the RPV specimen and 1.5 MHz 45 擄TRL FS20 probe is 3-23mm from the inner surface of the sample, covering the simulated ultrasonic crack area. Test results: the samples with defects were selected for verification ultrasonic scanning. It was found that there were three defects on the inner surface of the specimen, the length and height of which were 20.5mm / 7.4mm / 27.5mm / 13.1mm / 38.4mm / 15.4 mm respectively. There were no recorded defects in the weld seam and the heat-affected zone of both sides of the RPV ultrasonic test piece, which indicated that there were neither simulated cracks nor pores in the specimen. On the basis of the experimental results, this paper discusses the service environment and the mechanism of poor performance of the welding seam of pressure vessel dissimilar steel, the effect of grain size on ultrasonic inspection, and the relationship between simulation technology and ultrasonic testing. And the optimization of ultrasonic detection parameters of dissimilar steel weld in pressure vessel.
【學位授予單位】：東南大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TG441.7

【參考文獻】

相關(guān)期刊論文 前10條

1 李雙燕;;600MW壓水堆核電站蒸汽發(fā)生器焊接工藝與焊接材料[J];金屬加工(熱加工);2011年18期

2 張俊;丁輝;李明;張益成;陳懷東;呂天明;;核電站關(guān)鍵部件在役檢查可靠性分析[J];核動力工程;2011年04期

3 王鵬雁;楊永強;魏家斌;唐元生;;大口徑TP321+P11異種鋼焊接接頭裂紋的修復(fù)工藝[J];金屬加工(熱加工);2011年14期

4 韓恩厚;;核電站關(guān)鍵材料在微納米尺度上的環(huán)境損傷行為研究——進展與趨勢[J];金屬學報;2011年07期

5 柳越;胡林;王娟;;SA335-P91與P22異種鋼焊接工藝研究[J];石油和化工設(shè)備;2011年04期

6 蘇良驥;;SA335-P91與12Cr1MoV異種鋼的焊接工藝[J];焊接技術(shù);2011年03期

7 孫占;;核電站中奧氏體不銹鋼與碳鋼異種鋼焊接[J];金屬加工(熱加工);2011年04期

8 成海濤;趙彥芬;郭元蓉;張路;;我國核電用無縫鋼管國產(chǎn)化的新進展[J];鋼管;2011年01期

9 趙磊;曹志軍;葉峰;王佳旭;梅義俊;張鐵輝;;核電站蒸汽發(fā)生器安全端焊縫射線檢測技術(shù)[J];無損檢測;2010年11期

10 馬官兵;肖學柱;袁書現(xiàn);;反應(yīng)堆壓力容器主螺栓超聲波檢測技術(shù)[J];無損檢測;2010年10期

，

本文編號：1650643