High-strength bolt delayed fracture test method and apparatus thereof

Abstract

The invention relates to the field of bolt quality control, and especially relates to a method for examining a bolt under simulated actual use conditions, and an apparatus thereof. A high-strength bolt delayed fracture test method comprises the following steps: applying a constant tensile force F to a tested bolt according to the service environment of the tested bolt, simulating the service environment of the tested bolt, and determining the corrosion current density iS under the service environment; and changing the medium solution, the atmosphere and the temperature in an environment container, carrying out acceleration test, determining the corrosion current density iA, calculating to obtain a speed-up ratio, and carrying out acceleration test by using changed parameters to obtain the delay fracture resistance. A high-strength bolt delayed fracture test apparatus comprises a pressure ring and the environment container, the tested bolt is arranged in the environment container, and two ends of the tested bolt are fixedly connected with the pressure ring. The high-strength method and the apparatus thereof can be used for evaluating the delayed fracture resistance of the bolt under the stimulated actual service conditions of the bolt, and predicting the actual service life of the bolt in an acceleration test medium.

Description

technical field [0001] The invention relates to the field of bolt quality control, in particular to a bolt inspection method and device under simulated actual working conditions. Background technique [0002] High-strength bolts used in industrial atmosphere, marine atmosphere and marine environment often face the problem of delayed fracture. Delayed fracture refers to the phenomenon of brittle fracture suddenly occurring after the bolt has been in service for a period of time under stress. Relevant studies have shown that delayed fracture is caused by bolts. The corrosion electrochemical reaction that occurs during service leads to internal hydrogen permeation. In addition, the alternating load and material creep of bolts during service are also important factors that promote delayed fracture. In order to evaluate high-strength bolts, especially high-strength bolts above grade 12.9, research institutions at home and abroad have developed a series of evaluation methods. [...

AI Technical Summary

Problems solved by technology

This method is scientific to evaluate the performance of bolts from the perspective of fracture toughness, but this method is cumbersome and inconvenient for large-scale evaluation tests

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