Hydrogen Embrittlement Testing Evaluation Method Research Of Fasteners

High strength bolt connection is applied to all walks of life, is closely related to daily life. Due to its field widely used, its quality and safety issues directly related to social stability, personal property safety. The hydrogen embrittlement is one of the important factors affecting the quality of high strength fasteners, often show the delay fracture, its harmfulness is great, is an important subject that nots allow to ignore, also has caused extensive concern of the whole fastener industry and the users. Due to the hydrogen embrittlement of high strength bolt detection method is more, each have advantages and disadvantages, and time-consuming longer, so the industry need to be able to rapid and accurate method of detecting bolts hydrogen embrittlement.The blackning of the specifications for the M10,grade 10.9 and 12.9 high strength bolt samples, and the tensile stress corrosion slow strain method, parallel supporting surface method in combination with hydrogen embrittlement critical value, the fatigue life, break elongation, parameters, such as by mechanical properties and metallographic analysis experiment. The experimental data and the results are analyzed and compared, the results are as follows:1.For the high strength fasteners,parallel bearing surface method and the step method because of the long time,there will be loss of hydrogen diffusion in the sample, not very good to determine the critical value of hydrogen embrittlement;2. Due to the stretching rate is slower, the tensile curve, tensile strength, elongation and other parameters affect the full size bigger, so the slow strain rate test method can better determinethe risk of hydrogen embrittlement of high strength bolt, providing support for the rapid screening of bolt hydrogen embrittlement;3.By using slow strain rate tension combined with metallographic analysis method can quickly and accurately detect the hydrogen embrittlement, reduce the time,improve efficiency and detection rate,has great application prospects in the detection of the scene;4.Hydrogen embrittlement of high strength bolts has a certain impact and fatigue strength, fatigue test results can be used as an important basis for evaluation of the risk of hydrogen embrittlement of high strength fastener.Hydrogen embrittlement in rapid detection of high strength bolts in this paper has done some research and achieved certain results, puts forward a set of suitable for fasteners, hydrogen embrittlement testing, comprehensive assessment of the risk of hydrogen embrittlement method, Has established two non-standard method standard "rapid assessment method to assess risk of hydrogen embrittlement" and "slow strain tensile test method to assess risk of hydrogen embrittlement". It is advanced not only in the detection methods and technology,at the same time, in order to ensure the quality of high strength fasteners,fasteners to hydrogen embrittlement caused by accidents and provide the basis,and provide a reference for the use of high strength bolt assembly.