Strain Hardening Of Cryogenic Vessels From Austenitic Stainless Steels

Along with the development of low-temperature technology, the applications of cryogenic vessels from austenitic stainless steels are more and more wide.Since austenitic stainless steel has a low yield ratio and high price, it is necessary to study strain hardening of austenitic stainless steels, which can improve the technologic level and actualize the light design and manufacture of cryogenic vessels.Based on the literature review in and out of china and the principle of strain hardening, the technology of strain hardening is studied in this paper. The main research work and conclusions are as follows:(1) Experimental investigations on strain hardening vessel. Two strain hardening experiments of model vessels are processed. And the load-strain curve is gained by strain testing under different pressures in typical region.(2) Nonlinear numerical simulation of strain hardening process. The nonlinear numerical analysis models of strain-hardening process are established by considering effects of material nonlinear and geometry nonlinear. And two strain hardening processes of model vessls are numerical simulated. Also the law of the stress and strain changing with the load in strain hardening process is obtained which coincide with the numerical simulation results thus verifies the rationality of the numerical nonlinear analysis.(3) Research of the effects of strain hardening on mechanical properties. The mechanical testing samples are cut from the main weld of two model vessels after strengthening. And their mechanical properties are obtained by testing. The results show that the yield strength of austenitic stainless steel is improved remarkably, and good flexural and low-temperature impact properties are retained.