Abstracts Book - IMRC 2018

• SE2-P031
HYDROGEN PERMEABILITY PARAMETERS OVER A
MICROALLOYED STEEL SUBJECTED TO DIFFERENT THERMAL
CYCLES AND COOLING RATES
Julio César Villalobos 1 , Octavio Vázquez 1 , Héctor Vergara 1 , Adrian Del Pozo 2 , Bernardo
Campillo 3 , Sergio Serna 2
1 Instituto Tecnológico de Morelia, Posgrado en Ciencias en Metalurgia, Mexico. 2 Universidad
Autónoma del Estado de Morelos, CIICAP, Mexico. 3 Universidad Nacional Autónoma de México,
Facultad de Química, Mexico.
The principal aim of this work is to determine the hydrogen permeability
parameters such as: solubility, diffusion rate and hydrogen flux on an
experimental microalloy steel subjected to different thermal cycles and cooling
rates. These heat treatments consisted of a heating at 820 ° C and 900 ° C, and
accelerated cooling with rates of 21, 14, 12 and 9 °C/s. This caused a variety of
microstructures that consisted mainly of a mixture of martensite-bainite,
acicular martensite-ferrite, was obtained. To determine the diffusion kinetic
parameters, electrochemical permeability tests were carried out using a
Devanathan-Stachurski cell. In order to determine the number of reversible and
irreversible trapping sites, the hydrogen desorption curves were analyzed
permeability tests. The obtained results showed that a higher cooling rates
propitiates microstructures more susceptible to hydrogen embrittlement, due
to the fact that they present a greater number of irreversible trapping sites
(greater dislocation density) and a hydrogen concentration of approximately 1.3
ppmH producing decohesion and internal cracking.
Keywords: Microalloyed steels, Hydrogen permeability, Mechanical properties
Presenting authors email: juliocesar_fender@hotmail.com