【作者】 沈菊华；

【导师】 孙丽萍； 蔡勇； 冯大成；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋工程， 2011， 硕士

【摘要】 液化石油气(Liquefied Petroleum Gas,简称LPG)船是专门用来运输液化石油气的船舶,而液罐则是液化气船上的主要装备。近年来,液化石油气船的需求呈增长趋势,因此,液罐的制作能力也成为竞争的焦点。目前世界上只有美国、德国、英国、日本、韩国等为数不多的国家具有建造特种液化气罐的能力。国内也只有江南重工基本掌握了液罐的全套建造技术,但是生产方法相对还较落后,焊接主要还是以手工为主,效率相比欧美日韩还十分落后。因此,研究如何提高液罐制作中焊接效率及焊接质量是我国参与这一市场竞争的首要任务。本论文的研究对象为6500m3液化气船上的半冷半压式C型液罐,每船套共两个,1#罐为圆柱型单罐,2#罐为双耳型罐。该液罐的最低工作温度为-104℃,罐体结构钢板材料为X12Ni5低温钢。低温钢重要的特性是在低温工作条件有足够的强度、塑性、耐低温冲击。然而低温钢在焊接过程中易晶粒粗大,产生热裂纹,也经常会出现夹渣和未融合的缺陷。通过对低温钢性能和焊接性分析、低温钢传统手工焊及半自动/自动高效率气体保护焊焊接方法的分析以及几种焊接方法的试验研究,完成了该项目的焊接工艺评定并通过了船级社认证,其中半自动/自动高效率气体保护焊和横位置埋弧自动焊焊接方法在该项目的实际生产中也得以推广应用。此项焊接技术在液罐低温钢材料上的成功应用标志着我国液罐建造水平在国际上该领域有了一席之地。更多还原

【Abstract】 LPG Vessels are used specially to transport liquefied petroleum gas, whose tanks are important equipments. In recent years, the market demand of LPG Vessels is increasing and the ability of tanks building becomes competition focus. Until now, there are only a few countries that are able to make these special tanks in the world such as America, German, Japan, South Korea, and so on. In our country, Jiangnan Heave Industry company has mastered the whole set of techniques of tanks building, but product methods are far behind of other countries. Therefore, it is important to study how to improve welding efficiency and quality in tank building when our country takes part in the market competition.A C Semi-ref. Tank was studied in this paper which is equipped on the 6500 m3 LPG Vessel. There are two tanks, of which 1# tank is a cylinder type single tank and 2# is a double-ear type tank. The lowest operation temperature of the tanks is -104℃, and the steel material of the structure is X12Ni5. The main behaviors of this kind low temperature steel are that it can keep enough strength, plastic and impact-resistant under low temperature. When welding, However, some flaws may produced in the low temperature steel such as large crystalloids, thermal cracks, more often included slag and not fuse. By analyzing the behavior and weldablity of low temperature steel, and traditional manual welding and semi-automatic/automatic high efficiency gas protect welding and test study of other welding methods, it complete the arts and crafts assessment of welding and is certificated by classification society. The semi-automatic/automatic high efficiency gas protecting welding and transverse submerged arc automatic welding methods are developed to apply in the practical production The successful application of the welding technique in tanks made of low temperature steel material represents that the tanks building lever of our country improves a lot.更多还原