Inspection of barrelling of upset forgings based on digital photographs

Abstract

Majority of multi-cavity forging operations starts with descaling upset (e.g.: spindle) or with upsetting that results in significant deformation (e.g.: ring gear). During upsetting between parallel pressure plates the work-piece is getting barrelled. Barrelling is in close connection with friction coefficient. Till now the inspection of the shape of the work-piece getting barrelled was only limited to some references or to measurements of some work-pieces that were upset to barrel-shape [1] [2] [3]. More thorough observation requires application of statistical methods. We can obtain valuable information through statistics based on photographs taken during the production as well. Our present article reports on the methods we tried and on the results we obtained.