METHOD FOR ESTIMATING THE IMPACT STRENGTH OF PRODUCTS MADE OF BAINITICALLY QUENCHED CONSTRUCTION STEEL Russian patent published in 2021 - IPC G01N23/00 

FIELD: testing.

SUBSTANCE: invention relates to physical materials science, in particular, to non-destructive testing of construction steels in laboratory or factory conditions in various branches of industry. Substance: samples are produced in the form of indestructible standards, subjected to bainitic processing in the form of isothermal quenching in the entire bainite interval and in the entire transformation time interval. The resulting set of standards is used to test the level of impact strength, temperature and time of quenching of the tested product by the radiographic method. The total amount of residual austenite and the total amount of carbon in the residual austenite of each standard are determined by the radiographic method. After obtaining the data on the proportion of carbon in the residual austenite, graphs of the dependence of the proportion of carbon in the residual austenite relative to the total content of carbon in the steel, correlating with the level of impact strength in the standards, on the isothermal quenching mode in the entire bainite interval based on the temperature and holding time, are plotted on a single diagram. The level of impact strength of the tested product is obtained on the graph according to the value of the proportion of carbon thereof in the residual austenite as compared with the value of the proportion of carbon in the residual austenite of the standard.

EFFECT: possibility of conducting express testing for estimating the level of impact strength and operating life of the tested product made of bainitically quenched medium carbon alloy construction steel and determining the compliance with the preset level of impact strength while maintaining the integrity of the product.

1 cl, 5 dwg