Viscoplastic properties of chromium-nickel steel in short-term creep under constant stress. Part 1

Mechanical processing of Chromium-nickel steel machining (cutting, pressure treatment) is impossible without taking into account their short-term creep and ductility properties. The purpose of this work is to study the formation and deformation development under short-term creep and constant effective stresses. The results of experimental tests of chromium-nickel steel 12Kh18N10Т for short-term creep at room temperature are presented. A distinctive feature of the tests is the short-term creep in a wide range of stresses study: from the initial creep limit to the material destruction. The experiments were carried out under conditions of a stepwise increasing load (liquid pressure in a closed pipe) at a constant intensity of true stresses at each stage. It is shown that the conditions for changing the load, which ensure the constancy of the stress intensity, are violated at a sufficiently high voltage. Methods for separating the deformation into a plastic component and a component from short-term creep are proposed, which can be used both under conditions of stepped loading and under continuous loading. Examples of the occurrence and deformation development during short-term creep under conditions of decreasing stress are given.