Three-dimensional heat and material flow during friction stir welding of mild steel

Three-dimensional viscoplastic flow and heat transfer during friction stir welding of mild steel were investigated both experimentally and theoretically. The equations of conservation of mass, momentum and energy were solved in three dimensions using spatially variable thermo-physical properties and a methodology adapted from well-established previous work in fusion welding. Non-Newtonian viscosity for the metal flow was calculated considering temperature and strain rate dependent flow stress. The computed results showed significant viscoplastic flow near the tool surface, and convection was found to be the primary mechanism of heat transfer in this region. Also, the results demonstrated the strong three-dimensional nature of the transport of heat and mass, reaffirming the need for three-dimensional calculations. The streamlines of plastic flow indicated that material was transported mainly along the retreating side. The computed temperatures were in good agreement with the corresponding experimentally determined values.

[1]  Paul A. Colegrove,et al.  3-Dimensional CFD modelling of flow round a threaded friction stir welding tool profile , 2005 .

[2]  Chia-Jung Hsu.  Numerical Heat Transfer and Fluid Flow , 1981 .

[3]  T. DebRoy,et al.  Modeling of ferrite formation in a duplex stainless steel weld considering non-uniform starting microstructure , 2005 .

[4]  E. W. Hart.  Constitutive Relations for the Nonelastic Deformation of Metals , 1976 .

[5]  R. Ayer,et al.  Interface structure in a Fe¿Ni friction stir welded joint , 2005 .

[6]  Brian G. Thomas,et al.  Simple constitutive equations for steel at high temperature , 1992 .

[7]  Jamil A. Khan,et al.  Prediction of temperature distribution and thermal history during friction stir welding: input torque based model , 2003 .

[8]  Yuh J. Chao,et al.  Numerical simulation of transient temperature and residual stresses in friction stir welding of 304L stainless steel , 2004 .

[9]  Paul A. Colegrove,et al.  Development of Trivex friction stir welding tool Part 1 – two-dimensional flow modelling and experimental validation , 2004 .

[10]  P. Dawson,et al.  Modeling strain hardening and texture evolution in friction stir welding of stainless steel , 2005 .

[11]  Wei Zhang,et al.  Modeling of heat transfer and fluid flow during gas tungsten arc spot welding of low carbon steel , 2003 .

[12]  Zhili Feng,et al.  Heat Flow Model for Friction Stir Welding of Aluminum Alloys , 1998 .

[13]  R Kovacevic,et al.  Heat transfer modelling for both workpiece and tool in the friction stir welding process: A coupled model , 2004 .

[14]  T. Sheppard,et al.  Determination of flow stress: Part 1 constitutive equation for aluminium alloys at elevated temperatures , 1979 .

[15]  Radovan Kovacevic,et al.  Numerical and experimental study of the heat transfer process in friction stir welding , 2003 .

[16]  Tarasankar DebRoy,et al.  A heat-transfer and fluid-flow-based model to obtain a specific weld geometry using various combinations of welding variables , 2005 .

[17]  Wei Zhang,et al.  Integrated modelling of thermal cycles, austenite formation, grain growth and decomposition in the heat affected zone of carbon steel , 2005 .

[18]  Thomas J. Lienert,et al.  Numerical modelling of 3D plastic flow and heat transfer during friction stir welding of stainless steel , 2006 .

[19]  M. Mackay,et al.  The effect of metals on the processing of LLDPE through a slit die , 1994 .

[20]  R. Nandan,et al.  Numerical simulation of three-dimensional heat transfer and plastic flow during friction stir welding , 2006 .

[21]  Amitava De,et al.  Reliable calculations of heat and fluid flow during conduction mode laser welding through optimization of uncertain parameters , 2005 .

[22]  T. J. Lienert,et al.  Improved weldability diagram for pulsed laser welded austenitic stainless steels , 2003 .

[23]  Anthony P. Reynolds,et al.  Two-dimensional friction stir welding process model based on fluid mechanics , 2003 .

[24]  Patrick Ulysse,et al.  Three-dimensional modeling of the friction stir-welding process , 2002 .

[25]  Kaveh A. Tagavi,et al.  Influence of Material Properties and Forming Velocity on the Interfacial Slip Characteristics of Cross Wedge Rolling , 2001 .

[26]  J. C. Jaeger,et al.  Conduction of Heat in Solids , 1952 .

[27]  Øystein Grong,et al.  A process model for friction stir welding of age hardening aluminum alloys , 2001 .

[28]  V. I. Vill.  Friction Welding of Metals , 1962 .

[29]  Tarasankar DebRoy,et al.  NUMERICAL PREDICTION OF FLUID FLOW AND HEAT TRANSFER IN WELDING WITH A MOVING HEAT SOURCE , 1996 .

[30]  Paul A. Colegrove,et al.  Development of Trivex friction stir welding tool Part 2 – three-dimensional flow modelling , 2004 .

[31]  Jesper Henri Hattel,et al.  An analytical model for the heat generation in friction stir welding , 2004 .

[32]  C. J. Smithells,et al.  Smithells metals reference book , 1949 .

[33]  Tarasankar DebRoy,et al.  A computational procedure for finding multiple solutions of convective heat transfer equations , 2005 .

[34]  P. W. Fuerschbach,et al.  Composition change of stainless steel during microjoining with short laser pulse , 2004 .

[35]  F. Roger,et al.  Steady state thermomechanical modelling of friction stir welding , 2006 .

[36]  O. C. Zienkiewicz,et al.  VISCO-PLASTICITY--PLASTICITY AND CREEP IN ELASTIC SOLIDS--A UNIFIED NUMERICAL SOLUTION APPROACH , 1974 .