Influence of Welding Strength Matching Coefficient and Cold Stretching on Welding Residual Stress in Austenitic Stainles
- PDF / 4,584,794 Bytes
- 13 Pages / 593.972 x 792 pts Page_size
- 62 Downloads / 196 Views
JMEPEG https://doi.org/10.1007/s11665-018-3366-y
Influence of Welding Strength Matching Coefficient and Cold Stretching on Welding Residual Stress in Austenitic Stainless Steel Yaqing Lu
, Hu Hui, and Jianguo Gong
(Submitted December 22, 2016; in revised form February 6, 2018) Austenitic stainless steel is widely used in pressure vessels for the storage and transportation of liquid gases such as liquid nitrogen, liquid oxygen, and liquid hydrogen. Cryogenic pressure vessel manufacturing uses cold stretching technology, which relies heavily on welding joint performance, to construct lightweight and thin-walled vessels. Residual stress from welding is a primary factor in cases of austenitic stainless steel pressure vessel failure. In this paper, on the basis of Visual Environment 10.0 finite element simulation technology, the residual stress resulting from different welding strength matching coefficients (0.8, 1, 1.2, 1.4) for two S30408 plates welded with three-pass butt welds is calculated according to thermal elastoplastic theory. In addition, the stress field was calculated under a loading as high as 410 MPa and after the load was released. Path 1 was set to analyze stress along the welding line, and path 2 was set to analyze stress normal to the welding line. The welding strength matching coefficient strongly affected both the longitudinal residual stress (center of path 1) and the transverse residual stress (both ends of path 1) after the welding was completed. However, the coefficient had little effect on the longitudinal and transverse residual stress of path 2. Under the loading of 410 MPa, the longitudinal and transverse stress decreased and the stress distribution, with different welding strength matching coefficients, was less diverse. After the load was released, longitudinal and transverse stress distribution for both path 1 and path 2 decreased to a low level. Cold stretching could reduce the effect of residual stress to various degrees. Transverse strain along the stretching direction was also taken into consideration. The experimental results validated the reliability of the partial simulation. Keywords
cold stretching, numerical simulation, strength matching coefficient, welding residual stress, x-ray diffraction method
1. Introduction Stainless steel is classified by its crystal structure as ferrite stainless steel, austenitic stainless steel, martensitic stainless steel, duplex stainless steel, or precipitation-hardening stainless steel. Among the five types of stainless steel, austenitic stainless steel provides the best overall performance, most extensive range of alloy compositions, and greatest range of application. Increasing development of pressure vessels has coincided with the rapid expansion of the world economy and population. Austenitic stainless steel pressure vessels are extensively used for storing and transporting cryogenic media such as liquid natural gas (LNG), liquid nitrogen (LN2), liquid oxygen (LO2), and liquid hydrogen (LH2). The application of cold stretching technology for aust
Data Loading...
