Study On The Residual Stress Of TA1/Q235 Explosive Welding Composite Plate

With development of modern industry,the requirement for material is increasing.Explosive welding composite material with excellent comprehensive performance is widely applied to all walks of life.However,residual stress can arise easily in the explosive welding composite plate in the production process because of the high temperature,high pressure and large plastic deformation,which directly affect the quality and safety during working.Therefore,to measure and master the distribution rule of explosion welding residual stress so as to improve the product quality and structural safety has important theoretical and engineering significance.In this paper,the residual stress of the composite plate after explosive welding was measured by the blind hole method.The heat treatment process to eliminate the residual stress was developed then,and the influence of the heat treatment on the residual stress of the composite plate was analyzed.The results show that the residual stress in TA1/Q235 explosive welded composite plate is tensile stress state.The value of residual stress around detonation point is bigger than that of the periphery edge of the composite plate,which is attributed to the actual boundary effect.The stress state turns into compressive stress state after the composite plate go through the anneal process and spread with a sine wave along detonation wave propagation direction.The residual stress value after 540? heat treatment is smaller than other temperature.At the same time,finite element software Ansys/LS-Dyna was used to simulate the explosive welding process.The instantaneous parameters such as pressure field,velocity field,plastic strain field and equivalent stress field during explosive welding were analyzed.The simulation results show that the pressure at the edge of the composite plate is smaller while the plastic strain is larger,and the boundary effect such as tearing and non-welding occurs at periphery edge of the composite plate.The numerical simulation of the equivalent stress is larger than the blind hole test results for the simulation results is instantaneous results when the explosion occurs at 300?s,it has not experienced the process of cooling,phase change and aging.However,the simulation transient equivalent stress near detonation point is bigger than that of at the the periphery edge of the composite plate,which is consistent with the welding residual stress by the test.Finally,in order to study the effect of heat treatment on the bonding strength of the composite plate while eliminating the residual stress,the influence of different heat treatment temperature on the microstructure and properties of the composite plate was studied by metallographic analysis and basic mechanical property tests.It shows that the plastic deformation at the interface of TA1/Q235 composite plate is serious,and the plastic deformation microstructure is fibrous at Q235 base layer while it is mainly the adiabatic shear line at the TA1 flyer layer near the interface.With increase of anneal temperature,the microstructure occurs to recrystallization and grains grow up,deformation structure disappear gradually.The decarbonization appears at steel side and adiabatic shear line at the TA1 flyer layer completely disappeared after 540? and 700? annealing.The grain sizes become coarse after 700? anneal at the titanium side while it gets fine equiaxed grains after 540? anneal.The microhardness at the composite interface is larger than that of the both sides of the interface and shows a downward trend with increase of heat treatment temperature.In summary,the results show that 540? can be used as the stress relief annealing temperature of TA1/Q235 explosion composite plate in engineering practice.