Study On Pressure Strengthening Technology Of Cryogenic Vessels Made Of Austenitic Stainless Steels

Pressure strengthening technology of cryogenic vessels can significantly increase the allowable stress and thus reduce the wall thickness of the vessel. Consequently, it can save material, reduce the manufacturing cost of cryogenic vessels and increase the competitiveness of products.In this study, based on the relevant foreign standards and research results, test and finite element analysis were used to evaluate the feasibility of pressure strengthening technology, which can accumulate experience for the application of the technology in China.The main contents and conclusions of the study are summarized as follows:(1) The requirement of the pressure strengthening technology for materials was analyzed and validated by the tests for the domestic 06Cr19Ni10. The results indicated that the domestic 06Cr19Ni10 austenitic stainless steel is applicable to the pressure strengthening technology.(2) By combination of design method of pressure strengthening cryogenic vessels of austenitic stainless steels in the relevant foreign standards and the design method in China, the design method of pressure strengthening cryogenic vessels made of austenitic stainless steels in China was given. The method was used to design a fact vessel. It indicated that the wall thickness can be significantly decreased by using the pressure strengthening method.(3) The process of the pressure strengthening for the cryogenic vessel was simulated by using ANSYS software. The analysis of stress-strain distribution in the typical parts of the vessel was emphasized. The result shows that the cylinder of the vessel could be strengthened sufficiently while the head is insufficiently strengthened. However, it could not affect the safety of the whole structure.