Cold Stretch공법을 사용한 압력용기의 제작 및 소재특성에 관한 연구

Abstract

Due to the current global environmental problems and applying many restrictions on land and marine industries. In particular, with the restriction about the NOx, SOx and CO2 with regard to pollution of land and sea LNG, a clean fuel compared with conventional petroleum-based fuels, are using as alternative fuels. LNG has to carry and store in a specially dedicated insulated tank in a state in which liquefied natural gas is compressed to about 600 in the state of –162 ℃. The LNG storage and transport of small and medium-sized units are used in power plants and equipment of small particular storage facilities and has excellent mechanical and fatigue properties at cryogenic temperatures, and using austenitic stainless steel which has excellent cold working and processing property as a main material for the pressure vessel. The pressure vessel consists of the inner tank and the outer tank, the material of the inner tank is austenitic stainless steel, the outer tank is general carbon steel. As the storage amount increase, the size of the inner tank for LNG is also increased, which eventually increases the weight of the LNG storage tank. To make up for these shortcomings, Cold Stretch method based on austenitic stainless steels properties are being developed and used in the United States and China. Cold Stretch method is can be can transport and store the LNG in a larger amount as compared to the conventional pressure container, weight of the pressure vessel also can be reduced at 50 ~ 70% due to the thickness reduction. It is excellent effect in the economic and energy consumption point of view. Although, Cold Stretch has these advantages, the domestic situation is not even developed no laws. In this study, the actual production of pressure vessels of 15.232m3 capacity based on ASME Section VIII Div.1 are going to be processed with the Cold Stretch and to be checked the volume expansion, and to be compared the mechanical properties after the Cold Stretch.