Regular Article

Effect of rare earth Ce on the isothermal oxidation behavior in air of arsenic bearing steels

¹ School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Inner Mongolia, Baotou 014010, PR China
² Technical Center of HBIS Tangsteel Company, Tangshan, 063000, PR China
³ School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China

^* e-mail: lulu2910@126.com

Received: 13 May 2018
Accepted: 8 January 2019

Abstract

In order to study the segregation of arsenic impurities at the metal/oxide interface during high temperature exposure, isothermal oxidation behavior of arsenic bearing steels with various Ce content was systematically investigated. The result showed that oxidation mass gain of arsenic bearing steel in the temperature range of 950–1150 °C was decreased as a whole with increasing Ce content from 0 to 0.035 wt.%. At 1100 and 1150 °C, the best results are obtained for 0.027 and 0.035 wt.% Ce. Moreover, Ce addition could prevent grain boundaries oxidation, which reduced or even eliminated the formation of visible oxide particles along grain boundaries at 1000 and 1050 °C. In case of oxidation at 1050 and 1100 °C, the arsenic enrichment amount at the scale/metal interface was firstly decreased with increasing Ce content from 0 to 0.027 wt.% and then slightly increased as Ce content increased from 0.027 to 0.035 wt.%. This variation was attributed to the separation behavior of oxide scale, the formation of a continuous solid Fe₂SiO₄ layer and the arsenious rare earth particles promoted by Ce addition.