Studium mechanických vlastností a mikrostruktury svarových spojů modifikované 9% Cr oceli

Abstract

This PhD thesis is focused on welds made from 9-12% Cr heat resistant steel P92. P92 is promising steel for use in modern power plants with supercritical parameters. The critical part in terms of design life and operational safety are welded joints, that is why the PhD thesis focuses on research of properties of the P92 welded joints. The goal of theoretical part of the work is to summarize the available information about properties of P92 steel and weldment made from this steel. The main part of the work is experimental part, where the thermal cycle was measured. Based on this measurement the simulation of thermal cycles to the samples with size necessary to realize the mechanical properties measurement was carried out. In this work the metallographic investigation of real and simulated samples were made. Important part of the experiment is research of influence of the heat treatment to the mechanical properties. From the measured data the optimal mode of the heat treatment of P92 welds with the advantageous combination of mechanical properties is chosen.