In recent years, with the increasing popularity of cryogenic technology applications, the demand for austenitic stainless steel cryogenic vessel is growing. In order to improve the yield strength of austenitic stainless steel, strain strengthening technology came into being. After adopting this technology, the allowable stress of the material is greatly increased, and the wall thickness of the inner container can be reduced by about half when the wall thickness is determined by the tensile stress, which significantly reduces the weight and realizes the lightweight of the austenitic stainless steel cryogenic vessel.
In order to improve product competitiveness, NTtank (hereinafter referred to as the "Company") has initiated a project on strain strengthening technology for cryogenic container since July 2022. After the design of the test sample tank, stress analysis simulation calculation, material and welding material selection, welding process test, welding pre-tensile process evaluation and sample tank production, to the middle of September 2023, the company invited the expert group of the National Type Certificate Authority - Machinery Industry Shanghai Lanya Petrochemical Equipment Inspection Co., Ltd. to visit the site to witness the strain strengthening process validation test of sample containers. At present, the process verification test has successfully passed the certification.
The successful passing of the validation test of the process indicates that the company has mastered the strain strengthening technology of cryogenic container. Next, the technology will be applied to manufacture the first vacuum adiabatic cryogenic pressure vessel sample container and pass the low-temperature performance type test. After obtaining the type test certificate, the company will have the qualification of mass production of mobile vacuum adiabatic cryogenic pressure vessels by applying strain strengthening technology.