Standards Development

Scope

This international Standard specifies the required guidelines to evaluate the stress change between two states of the same materials from indentation force differences using the instrumented indentation test and sharp indenters to measure test force and indentation depth. This standard applies to the range of force from 1 mN to 3 kN (see Table 1 of ISO 14577-1:2015). This standard for measuring stress semi-nondestructively makes it possible not to sample in-service components and includes enough testing volume for nano- and micro-scale materials to be assessed usefully.

A target material can be identified as any in-service-component or manufactured product exhibiting internal stresses or induced strains associated to stress change that are worth measuring using the proposed method. Parts or materials affected by residual stresses induced by any process or loading condition can be treated as target materials and these stress change can be determined using this Standard. A reference material is a material possessing in general an identical chemical composition and mechanical properties to those of the target material.

Purpose

To provide a new quantitative technique to evaluate stress change semi-nondestructively with indentation force difference.

There is an international standard to evaluate residual stresses by neutron diffraction (ISO/TS 21432: 2005, Non-destructive testing - Standard test method for determining residual stresses by neutron diffraction).

The proposed new technique can be used assess stress change between the two locations of same materials quantitatively.

This International standard for measuring stress change does not need to be sampled for components, and only small regions for measurement are utilized.