Evolution of Plastic Strain During a Flow Forming Process

TL;DR

This study investigates how plastic strain varies through the thickness of steel plates during flow forming, revealing surface strain concentrations and providing empirical models for strain distribution related to process parameters.

Contribution

It introduces empirical expressions that describe the contribution of roller and mandrel to local plastic strain during flow forming of steel plates.

Findings

Plastic strain is higher at surfaces, lower at the center.

Empirical models relate strain distribution to thickness reduction.

Strain distribution depends on forming conditions.

Abstract

The distribution of equivalent plastic strain through the thickness of several AISI 1020 steel plates formed under different conditions over a smooth cylindrical mandrel using a single-roller forward flow forming operation was studied by measuring the local micro-indentation hardness of the deformed material. The equivalent plastic strain was higher at the inner and outer surfaces and lowest at the center of the workpiece. Empirical expressions are presented which describe the contribution of the roller and mandrel to the total local equivalent plastic strain within the flow formed part. The dependence of these expressions upon the thickness reduction during flow forming is discussed.