【正文】 沈陽工學(xué)院畢業(yè)論文 I 摘要 低溫壓力容器多數(shù)在低溫高壓下運行，必須要承受較高的載荷。因此，要求壓力容器的焊縫和熱影響區(qū)必須具有較高的強度、足夠的沖擊韌性，并且保證焊接接頭無裂紋、夾渣、氣孔等缺陷。 本課題研究的是低溫壓力容器用不銹鋼 0Cr18Ni9 焊接工藝的研究。針對 0Cr18Ni9鋼，分析了 0Cr18Ni9 鋼的焊接材料、焊接方法及焊接工藝。采用試板焊接和不同坡口形式對 0Cr18Ni9 鋼焊接工藝進行了試驗研究，用 JBD－ 300 低溫 Charpy 沖擊試驗機、硬度測試儀和焊接接頭低溫力學(xué)性能進行了測試。為探明焊接工藝 對接頭組織與低溫斷裂韌性的影響規(guī)律，對試樣進行了光學(xué)顯微觀察、電子掃描電鏡分析等試驗。 試驗結(jié)果表明： 0Cr18Ni9 鋼低溫韌性的影響的基礎(chǔ)上，根據(jù)相關(guān)試驗標(biāo)準(zhǔn)對 0Cr18Ni9鋼焊接性進行了試驗研究。組織金相圖譜果表明，雙面 V 形坡口的低溫韌性與母材相比有所提高，但提高幅度相對粗晶區(qū)要小的多。 熱影響區(qū)的最高硬度 HV10在 350 左右，雙面 V形坡口和 K 形坡口的抗裂性能優(yōu)良。 不同坡口接頭的不同位置的沖擊韌性變化很大，在熔合線附近低溫沖擊韌性最低，距離熔合線越近沖擊功越小，越遠沖擊功越大。在熔合線上隨著焊縫所 占比例的增加，沖擊試樣的低溫沖擊功在不斷減小。焊接試驗表明， 0Cr18Ni9 鋼在 165℃沖擊功最低值為 (雙面 V 形坡口 )、 (K 形坡口 )。能夠滿足 BS7777 和 ASME 標(biāo)準(zhǔn)中對低溫儲罐低溫韌性的要求。 同過兩種不同坡口形的對比雙面 V 形坡口的個方面焊接性能要比K 形坡口要好。 關(guān)鍵詞 ： 低溫壓力容器； 0Cr18Ni9 鋼； K 形坡口；雙面 V 形坡口 沈陽工學(xué)院畢業(yè)論文 II Abstract Most low temperature pressure vessel under high pressure in low temperature operation, must carry the higher load. Therefore, the requirements of the pressure vessel welding seam and heat affected zone must have high strength, sufficient impact toughness, and ensure that welded joint has no defects such as cracks, slag inclusion and porosity. This topic is the study of the low temperature pressure vessels used stainless steel 0 cr18ni9 welding technology research. Aiming at 0 cr18ni9 steel, analyzes the 0 cr18ni9 steel welding material, welding method and welding technology. Use test board welding and different groove form of 0 cr18ni9 steel welding technology were studied, using the JBD 300 cryogenic Charpy impact tester, hardness tester, and welded joint mechanical properties at low temperature was tested. Welding process of joint anization and its the influence law of fracture toughness at low temperature, optical microscopic observation of sample, test, such as electronic scanning electron microscopy (sem) analysis. Experimental results show that: 0 cr18ni9 steel on the basis of the influence of low temperature toughness, according to the relevant test standard of 0 cr18ni9 steel weldability is researched. Organization metallographic atlas fruit shows that double V groove of the low temperature toughness pared with the parent metal, but increase relatively coarse grain zone is much smaller. The highest hardness HV10 at around $350, double V groove groove and K the crack resistance of good performance. Different distance groove joint position change is very big, the impact toughness of lowest near the fusion line low temperature impact toughness, the closer distance fusion line of impact energy is smaller, and the greater the impact is. On the fusion line along with the increase of the proportion of weld impact specimen is that the low temperature decreases. Welding test showed that 0 cr18ni9 steel in low 165 ℃ impact energy of J (double V groove), J (K) groove. Can satisfy the BS7777 and ASME standards for low temperature storage tank in low temperature toughness. With two different slope synchronized to contrast double V groove in the aspects of welding performance is better than K groove. Key words: low temperature pressure vessel。 0 cr18ni9 steel。 K groove。Double V groove 沈陽工學(xué)院畢業(yè)論文 III 目 錄 摘要 ............................................................................................................................................. I Abstract.......................................................................................................................................II 第 1 章 緒論 .............................................................................................................................. 1 低溫壓力容器介紹 ...................................................................................................... 1 國內(nèi)外研究與應(yīng)用狀況 ............................................................................................. 1 低溫壓力容器所用材料 .............................................................................................. 3 0Cr18Ni9 鋼焊接中存在的問題 ................................................................................. 4 本文主要研究目的及內(nèi)容 ......................................................................................... 5 第 2 章 試驗材料與試驗方法 .................................................................................................. 6 試驗材料 ..................................................................................................................... 6 實驗用鋼的化學(xué)成分及力學(xué)性能 .................................................................. 6 試驗材料的金相組織 .................................................................................... 7 低溫儲罐