The "Determination of Residual Stress in Metallic Materials - Total Release Strain Method" has been officially released

The national standard "Determination of Residual Stress in Metallic Materials - Total Release Strain Method", jointly drafted by Wuhan Iron and Steel (Group) Corporation, Institute of Metal Research, Chinese Academy of Sciences, Shenzhen Wance Test Equipment Co., LTD., Naval University of Engineering and other units, was granted the standard number GB/T 31218-2014 by the Standardization Administration of the People's Republic of China. It was officially promulgated on September 30, 2014 and came into effect on May 1, 2015.

According to the principle of the total release strain method, when the cut sample is small enough that the macroscopic residual stress distribution gradient on it can be ignored, the macroscopic residual stress will be fully released. By detecting the strain released by the strain gauge on it, the residual stress before release can be obtained. As the adhered strain gauges have a certain size and dimension, in order not to cause damage to them, the size of the small specimens cut in this article reaches 10×10×10mm. It can be basically considered that the residual stress on them has been completely released.

The existence of residual stress often has a significant impact on the use of components (especially welded products), such as accelerating fatigue fracture and promoting stress corrosion cracking. The main method to understand the magnitude and distribution of residual stress is stress measurement. The completion of the drafting of this standard will play a significant role in promoting the technical level of residual stress determination both in China and internationally.