Thermal modeling of friction stir welding of stainless steel 304L

Abstract

This paper presents a numerical model, based on the displacement of one point of the material flow relative to a fixed reference point, in order to formulate the heat generation during friction stir process and thereby calculate the temperature difference between advancing and retreating sides. This model considers frictional heating dependent on both the temperature and the velocity of the tool, as well as heat generation due to plastic deformation dependent on temperature, and assumes that friction heat at high temperature was replaced by heat generation due to plastic deformation. The heat generated by plastic strain energy dissipation in thermomechanically affected zone is calculated by a new technique, and the convection heat transfer coefficient and the sticking state parameter are considered as a function of temperature. Finally, the thermal equations are solved using a nonlinear finite element code ABAQUS. The numerical results correctly showed the asymmetric nature of temperature distributed at different sides of the weld line which have good agreement with experimental data that are presented in the literature.

Modelling of friction stir welding of DH36 steel

“…Heat partition between the tool and the workpiece Tool parts are expected to gain heat more than the workpiece during FSW due to the low thermal conductivity of DH36 steel (as received from the manufacturer = 45-55 W/m.K) compared to the tool types (PCBN) which is about three times that of steel. The partition of heat between tool and workpiece has been calculated by other researchers [2,21] as follows:…”

“…Lower plastic deformation due to the lower viscosity at the front of the tool surface has been given as a reason for this minimum temperature. Darvazi et al [21], through numerical modelling, found that the maximum temperature in FSW of stainless steel 304 L was in the back half of the shoulder region and towards the advancing side. They also found that there was more asymmetry in temperature under the shoulder compared to the regions away from it.…”

Microestrutura de uma Solda Dissimilar entre o Aço Inoxidável Ferrítico AISI 410S e o Aço Inoxidável Austenítico AISI 304L Soldado pelo Processo FSW

“…De acordo com os resultados de Darvazi and Iranmanesh [20] para a simulação térmica do aço inoxidável austenítico AISI 304L com espessura de 3,2 mm, existe um gradiente de temperatura entre a região do topo e do fundo da junta soldada, como pode ser observado na Figura 6. Tal resultado é suportado por outros estudos [21].…”

“…Distribuição de temperatura na seção transversal da solda FSW do aço inoxidável austenítico AISI 304L [20]. É possível comprovar por esta imagem o diminuto tamanho dos grãos na ZM-I.…”

Interface behavior and mechanical properties of 316L stainless steel filling friction stir welded joints

“…The named auto-adjusting or retractable or double-acting FSW equipment is complex and expensive. As for high melting point materials, it is almost impossible due to the limitations of pin tool design [8][9][10]. Conventional refilling methods by fusion welding technology result in a serious decrease of joint performance.…”