Residual Stress Test And Analysis Of Main Inlet Valve No.1

The welding residual stress exists in big welding structure inevitably, andseriously influences the mechanical property of structure. Therefore, accurateeliminate and measurement of residual stress is very important. The main purpose ofthis paper is to study the methods of testing and analy zing the Main Inlet Valve No.1which product by one company. Through the analysis of the effect of Vibratory StressRelief (VSR) and Thermal Stress Relief (TSR) to eliminate residual stress developedan advanced technology in line with national standards, then provided a theoreticalbasis for the VSR through the experiment modal analysis of the valve.The paper described the existence reason of residual stress, residual stressclassification, and residual stress harm. To eliminate the welding residual stress isnecessary. It listed some methods of eliminating residual stress, and analyzed theeffect of all the methods, and based on the destruction and non destruction of thematerial proposed a variety of methods of testing residual stress. According the needof experiment and research object, used VSR and TSR to eliminate residual stress andtest residual stress by blind-hole method.The paper did a strain date collecting by the data acquisition system product byNI Company, and then analyzed the offline date by Matlab software. T he experimentalresults showed that the residual stress elimination rate by used VSR were higher thanTSR. After the experimental modal analysis of the valve, we got the first modalfrequencies, well very close to the frequency of VSR. Through the research andpractical verification, the paper establishes a feasible to eliminate welding residualstress of large welding parts, promoting the theoretic analysis of residual stress andinstruction, promoting the application of VSR on large welding product analysis andengineering.