Experimental study on slow strain rate tension of bolt under corrosive environment
In view of the problem that the bolt is prone to corrosion in corrosive medium water leading to failure of the bolt support,chemical composition of the commonly used bolts in coal mines was analyzed,and the SSRT test was carried out with the slow strain rate stress corrosion testing machine,and the fracture morphology was compared.The results show that,the bolts in the standard solution show high stress corrosion sensitivity,the sensitivity of the plastic parameters is greater than that of the strength parameters,and the plastic parameters are lower than the values in air.Surface-treated bolts still show stress corrosion sensitivity,mainly reflected in the reduction of elongation,especially at strain rates of 1×10-5 s-1 and 1×10-7 s-1.In addition,the tensile rate is directly related to the fracture morphology of SCC,and the larger the tensile rate,the closer the fracture method is to the plastic fracture,and the smaller the tensile rate leads to the brittle fracture characteristics of the material.In general,when designing and using corrosive bolts,it is necessary to consider its stress corrosion sensitivity index,and pay attention to controlling the tensile rate in actual use to reduce the influence of the stress corrosion sensitivity of the specimen.
boltsmine watertensile ratestress corrosion sensitivity index
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