The invention relates to the technical field of ultrahigh strength steel delayed
cracking performance testing, in particular to an ultrahigh strength steel delayed
cracking performance testing device and a testing method thereof.The testing method includes the following steps that firstly, a rectangular strip sample is
cut from a to-be-tested ultrahigh strength steel plate, the width of the sample is 10-20 mm, the thickness of the sample is 0.5-6.0 mm, and the thickness of the sample is 10-20 mm; performing oil removal,
grinding and ultrasonic cleaning, and recording a surface treatment mode; step II, bending the sample into a bending state according to a U shape, and enabling the surface of the outer layer to generate maximum
surface strain, the method can be used for rapid screening and can also be used as a preposed step for threshold and
life evaluation, the consistency and comparability of results between different laboratories and
engineering units can be improved, and the method is suitable for large-scale popularization and application. And through
hydrogen-free contrast, fracture microscopic analysis, diffusible
hydrogen detection and finite element check, macroscopic crack behaviors are associated with microscopic fracture characteristics and
hydrogen content, so that the capability of judging a fracturing mechanism is enhanced, and a reliable basis is provided for
engineering material type selection and
process verification.