The Study About The Effect On Stress Distribution Of The TA15Sheet With EBW And Heat Treatment After Welding

This article is based on heat transfer, thermal elastoplastic theory, the smalldeformation theory and finite element method, the study analyzed the process ofelectron beam welding and electron beam local heat treatment after weldingtemperature field and stress field distribution. Take TA15titanium alloy sheet as thenumerically simulated research object, combining with experiments.Results show that the thermal cycle curve of EBW and EBHT conforms to thecharacteristics of EBW and EBHT.It can see shape of wide and below naroow ofEBW and EBHT of the surface heat source of the circular shape.In stress field of EBW and EBHT as you can see, the two processes of residualstress is mainly concentrated in the region of the weld center and close to weld,transverse residual stress is less than50MPa, relative to the longitudinal stress of600Mpa is small.And longitudinal stress by EBHT is reduced to475Mpa, thereduction was achieved21%.EBHT on the back of the weld, relative to in front, cansignificantly reduce the residual stress of workpiece; In the case of other parametersunchanged, with the increase of width of heat treatment or decrease the speed ofheat treatment, the welding residual stress reduce.It was optimized on the basis of infrared temperature measurement system invacuum, selection of itself with the function of wireless transmission acquisitioncard and temperature sensor AD590.At room temperature, the thermometertemperature value and the reading on the acquisition software has about2.04%certain error.AD590after collection,the average error is7.42%.Protect shell forpressure, vacuum tightness and fatigue test, it shows that the system is seal intactand system is stable.Use optimization system to collect temperature of50HZ lamp,it gains the cycleof20ms sine wave of the temperature.The change of temperature gained by AD590is not large,relatively stable.Use release method to measure residual stress of EBWand EBHT, results show that the measurement and the numerical simulation resultsof the distribution is consistent. Microstructure of weld appearance compared withtemperature field simulation of solidliquid interface is consistent.Take tensile andmetallographic test, after the EBHT of workpiece, a finer microstructure of the weldand high strength. Further verification about the accuracy of the models,at the sametime provides the guarantee for the temperature control of heat treatment.