0Cr18Ni9钢压力容器焊接工艺的研究-毕业论文.doc

摘要 低温压力容器多数在低温高压下运行，必须要承受较高的载荷。因此，要求压力容器的焊缝和热影响区必须具有较高的强度、足够的冲击韧性，并且保证焊接接头无裂纹、夹渣、气孔等缺陷。 本课题研究的是低温压力容器用不锈钢0Cr18Ni9焊接工艺的研究。针对0Cr18Ni9钢，分析了 0Cr18Ni9钢的焊接材料、焊接方法及焊接工艺。采用试板焊接和不同坡口形式对0Cr18Ni9钢焊接工艺进行了试验研究，用 JBD－300 低温 Charpy 冲击试验机、硬度测试仪和焊接接头低温力学性能进行了测试。为探明焊接工艺对接头组织与低温断裂韧性的影响规律，对试样进行了光学显微观察、电子扫描电镜分析等试验。 试验结果表明：0Cr18Ni9钢低温韧性的影响的基础上，根据相关试验标准对0Cr18Ni9钢焊接性进行了试验研究。组织金相图谱果表明，双面V形坡口的低温韧性与母材相比有所提高，但提高幅度相对粗晶区要小的多。 热影响区的最高硬度 HV10在350左右，双面V形坡口和K形坡口的抗裂性能优良。 不同坡口接头的不同位置的冲击韧性变化很大，在熔合线附近低温冲击韧性最低，距离熔合线越近冲击功越小，越远冲击功越大。在熔合线上随着焊缝所占比例的增加，冲击试样的低温冲击功在不断减小。焊接试验表明，0Cr18Ni9钢在-165℃冲击功最低值为 75.7J(双面V形坡口)、71.3J(K形坡口)。能够满足 BS7777 和 ASME 标准中对低温储罐低温韧性的要求。 同过两种不同坡口形的对比双面V形坡口的个方面焊接性能要比K形坡口要好。 关键词：低温压力容器；0Cr18Ni9钢；K形坡口；双面V形坡口 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 organization 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 th