Assessment of metal deformability at cold forming of internal spline surfaces

Abstract

Ogorodnikov V. A., Kyrytsia I. Yu. Assessment of metal deformability at cold forming of internal spline surfaces. Material working by pressure. 2020. № 1 (50). Р. 136-146.

Assessment of the deformability of workpieces in pressure treatment is based on the phenomenological theory of deformability, the advantage of which over other theories of fracture is that it takes into account the effect of the loading history on the intensity of damage accumulation. The modern theory of deformability is based on the hypothesis of the dependence of plasticity on the stress state diagram, which is described by the plasticity diagram. The theory of deformability also allows one to obtain a quantitative assessment of the influence of the parameters of the technological process on the probability of fracture and, on the basis of this, rationally use the reserves of plasticity.

In this paper the process of forming internal spline surfaces in blind holes by the cold plastic deformation method (CPDM) is investigated. The expediency of research of mechanics of process forming spline workpieces is shown. Distribution of hardness in meridian section of workpieces that has allowed to prepare the initial information for calculation the stress-stained state (SSS) in view of hardening metal is received.

The stress-stained state (SSS) is investigated and the deformability of metal is estimated at forming internal spline surfaces in blind holes by the cold plastic deformation method (CPDM). The experimentally-calculated method was attracted for calculation of the stress state, this method combining the method of hardness and an engineering method. Distribution of tensor stress components and the stress state index are obtained. The used resource of plasticity at forming internal spline surfaces in blind holes by the CPDM is estimated.