Nano-Preciptates Design with Hydrogen Trapping Character in High Strength Steel

Abstract

Nano-precipitates of alloy carbides TiC, NbC and VC which have the same NaCl-type crystal structure in tempered martensite have been characterized by means of high-resolution transmission electron microscope (HRTEM) and correlated to the hydrogen trapping property. The examination of whether the amount of hydrogen absorbed by the TiC particles depends on their surface area or volume indicate that the coherent and semi-coherent TiC particles trap hydrogen at the precipitate/matrix interface at ambient temperature while the incoherent TiC particles trap hydrogen inside themselves only at high temperatures. Coherent and semi-coherent NbC and VC particles also demonstrate a surface area dependence of hydrogen trapping capacity with NbC > TiC ≫ VC. Contrary to TiC, incoherent NbC and VC particles are unable to trap hydrogen.

This article was originally published in “Effects of Hydrogen on Materials”, ASM International, ISBN-13: 978-1-61503-003-3, (2009), pp. 448–455.