Dissertation > Excellent graduate degree dissertation topics show

Study on Strain Hardening of Austenitic Stainless Steel Cryogenic Vessels

Author: ZhangWenJian
Tutor: JiangZuo
School: South China University of Technology
Course: Chemical Process Equipment
Keywords: austenitic stainless steel cryogenic vessel strain hardening finite element
CLC: TQ053.2
Type: Master's thesis
Year: 2011
Downloads: 45
Quote: 1
Read: Download Dissertation

Abstract

For its good plasticity and toughness but with low yield ration, austenitic stainless steel is commonly used in the manufacture of cryogenic pressure vessels. Using the strain hardening technology to design cryogenic vessels can reduce the vessels’wall thickness and weight, save the vessels’transportation energy consumption and achieve green manufacture.The tests of the mechanical properties of domestic austenitic stainless steel 06Cr19Ni10 are done to research the influencing factor of strain hardening which provide guidance for strain hardening; Plastic instability behavior of thin-walled cylinder vessel under internal pressure is studied considering strain hardening and deformation, and it is proved that during the process of strain hardening, the bearing capacity of structural does not change. Finite element analysis and theoretical calculation of strain hardening process of austenitic stainless steel cryogenic vessels are done, the distribution of stress and strain of the vessels are simulated, the burst pressure and the safety margin are calculated, to provide guidance for strain hardening design and experiments.The main content and conclusions of the study are summarized as follows:(1)The mechanical properties test of domestic austenitic stainless steel 06Cr19Ni10. First, the physical dimension of tensile specimens affects the plasticity index; Second, the larger pre-strain, the higher the yield strength, the higher the yield ratio, the smaller the elongation of the material; Third, the treatment of pressure holding could improve the yield strength and make the tensile strength and elongation after fracture lower; Fourth, A faster strain rate leads to a higher yield strength and a lower tensile strength and a lower elongation after fracture;(2)The study on limit load-carrying capacity of thin-walled cylindrical vessel with considering strain hardening of material. It is proved that load-bearing capacity of pressure vessel has nothing to do with the loading history while considering both the strain hardening effect of material and the deformation of the structure by theory analysis and finite element simulation, so strain hardening doesn’t change the limit load-carrying capacity of structure. So the method which the design of strain hardening vessels’demission based on the initial ones is reasonable;(3)Non-linear numerical simulation on strain hardening of austenitic stainless steel cryogenic vessel. The numerical analysis result of the non-linear finite element analysis model is in good agreement with the experimental. The model can be used for stress-strain analysis of complex structure strain hardening cryogenic vessels; The proposal of maximum 5% plastic deformation of actual vessel in the subject away from the discontinuity in the process of strain hardening of domestic austenitic stainless steel is put forward based on the safety margin of different pre-strain and domestic austenitic stainless steel has the characteristic of high yield strength and combined with foreign strain hardening design method.

Related Dissertations

CLC: > Industrial Technology > Chemical Industry > General issues > Chemical machinery and apparatus, equipment > Chemical general machinery and equipment > Container chemical equipment
© 2012 www.DissertationTopic.Net Mobile