Possibilities of Restoring the Plasticity of Operationally Degraded Steel EN ISO 14MoV6-3

Abstract

The article deals with the possibility of increasing mechanical and utility properties by means of regenerative heat treatment. Experimental program is focused on the heat treatment of low-alloy heat resistant steel EN ISO 14MoV6-3. Currently, due to significant metallographic changes, this steel is already in most cases operated in a very brittle state as a result of operational degradation. The high brittleness of the steel in operation is the source of frequent failures in the piping systems of coal-fired power plants. For this reason it is highly desirable to achieve an increase in its toughness through appropriate heat treatment and thereby achieve an adequate increase in the remaining service life. It should be noted that increasing the residual life using heat treatment is much more economically advantageous and also less time-consuming compared to the implemented repairs of sudden failures. When designing the heat treatment procedure it is also necessary to respect the specifics of heating and cooling of massive material such as thick-walled pipes. In addition the heat treatment process must be feasible directly at the location of the pipeline structure.