The Study On The Process Of Mechanical Expanding And Optimization Of The Technologic Parameters

The mechanical expanding is a key process to produce large size LSAW pipe for pipeline, which adopts UOE, JCOE forming methods,and so on. To a fair degree, this processing determines the quality of the final products.This paper focuses on the analysis of the force and energy parameters of mechanical expanding and the deduction of the formulas of expanding force and expanding stroke. Compare with the existing research findings, both thin-walled pipe and thick-walled one are discussed on the force borne in per unit area on the expanded billet, and the formulas are given for calculating the force. For the expanding stroke, the paper takes the actual production process (there is still an idle stroke before expanding) into account and derives the formula for calculating the idle stroke so that the formula for calculating the stroke is more precise and closer to reality.This paper is aiming at four kinds of billet with designation of 406×7.4mm,711×11.1mm,1016×18mm and 1422×26.4mm, and makes an simulation analysis of the mechanical expanding forming process by MARC software. The result of comparation shows the characteristics in the process of billet deformation, the laws of stress and strain distribution and the elastic recovery , etc. It also analyses the effects caused by the mechanical expanding process parameters on the final products.On the basis of the FEA simulation software MARC, the orthogonal experimental method is introduced for optimizing the combination of the main process parameters of various mechanical expanding products with a target of the dimensional accuracy and shape accuracy of products. The analysis and discussion on the result shows the effects caused by each factor on the quality of the final products and provides the optimized combination. The optimized process parameters will be propitious to improve the precision of the size and shape of the products.Based on the research of mechanical expanding process and the analysis of the effect caused by the process parameters on the quality of the final products, a mechanical expanding experimental equipment is designed and the processing and manufacturing activities are completed.