Study On Welding Residual Stress And Shrinkage Deformation Of Duplex Stainless Steel 2205

Duplex stainless steel is a kind of steel which has the organization of half solid-quenching austenite phase and half ferrite phase, and in general the least content is a minimum of 30%. Duplex stainless steel has the advantages of both austenitic stainless steel and ferritic stainless steel,which has the salient features of resistance to chloride corrosion resistance, pitting resistance, stress corrosion and others. In recent years, it has been widely used more and more in the petroleum chemical industry, offshore engineering, ship construction and other areas, with a great trend to replace the austenitic stainless steel.The key to the successful application of duplex stainless steel is welding. Due to the vast majority welding production using a local heating method, it will inevitably cause stress and deformation. Welding stress and deformation not only can lead to hot cracking or cold cracking process defects, but also affect the strength and stiffness of weldments to a certain extent. In addition, the welding stress and deformation also affect the machining precision of weldments and dimensional stability. Welding residual stress is an important indicator which affects the structural strength and performance, and the amount of shrinkage deformation can be used to determine the correct welding process welding margin. Therefore, setting up an accurate prediction of welding residual stress and deformation of the welding structure is an important issue which is urgently needed to solve.With the background of the project from Chongqing Science and Technology Commission which is called the "Research on Special Shipping Welding Technology (CSTS2008AB3033)", the main features of duplex stainless steel and its significance of the application in the manufacture of the special ship have been discussed in this paper, with an overview of domestic and international research dynamics on welding stress and deformation of duplex stainless steel. Taking duplex stainless steel 2205 plate welding for an example, A dynamic simulation of welding process has been achieved in the large-scale finite element software ANSYS, analysis of and welding temperature field and stress field characteristics have been analyzed, and in the last the of distribution welding residual stress has been acquired. The duplex stainless 2205 steel plate welding experiment has been conducted in the state-run Shipyard Chuandong to test the welding deformation and residual stress shrink the size, and compared the calculated values and simulation to verify the correctness and feasibility of simulation. Based on a large number of welding, Prediction models about the most residual stress and shrinkage deformation of duplex stainless steel 2205 welding have been respectively established, using a variety of mathematical methods, such as multiple linear regression, BP neural networks and support vector machine (SVM),which has a guiding role for duplex stainless steel 2205 welding process specification development and improving the quality of welding, and which has an important significance for promotion and application of the duplex stainless steel 2205 in the manufacture of special ship.