HYDROGEN PERMEATION AND ITS EFFECT ON MECHANICAL PROPERTIES OF PIPELINE STEELS

Abstract

This work is literature review plus experimental work done on hydrogen embrittlement of line pipe steels different grades to get prepared to carry out research work on X65 line pipe steel grade by using non-conventional heat treatment method by heating the sample to austenitizing temperature of 1150 °C and then holding at this temperature for 10 minutes followed by cooling in different viz. ice water quenching, oil cooling and air cooling to get different microstructures. There is a high demand in steel industry to develop higher grades of line pipe steels to increase the efficiency of natural gas transportation. The development is two-fold as development of high strength line pipe steel can be used in future for transportation of future fuel hydrogen which will be economic and benefit us in preparing for upcoming era of hydrogen economy. High strength pipelines can also be used for transportation of larger volumes of fuel under high internal pressure. In this work an API X65 steel has been developed through non-conventional heat treatment to create different microstructures. To assess the effect of heat treatment, mechanical properties are evaluated. The mechanical properties will also be evaluated after cathodic charging of samples which will be shown in our future work. In this way, a systematic data will be obtained to analyse effect of hydrogen embrittlement on different microstructures of API X65 line pipe steel.