An estimation of residual plasticity and crack resistance of locally deformed zones of welded designs

Abstract

The technical condition of the load-lifting cranes, belonging to the dangerous industrial objects, is defined by a technical condition of bearing metalworks and demands constant quality assurance of connections and units. Special danger is represented by welded seams near to which there are the local plastically deformed zones leading to the brittle behavior of metal and to crack formation. A method of an estimation of crack resistance, based on measurement in the specified zones of hardness on Brinell and definition on its value of level of plastic damage of metal, and also of the remained stock of plasticity, is offered. The method differs in simplicity of execution, profitability and high reliability of results of research. It allows to carry out the current control of a condition for the purpose of definition of degree of danger and an establishment of a deadline of service of a design.