Regular Article

Influence of continuous annealing soaking temperature on fish-scaling resistance of ultra-low carbon steel for porcelain enameling

¹ School of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing, PR China
² Shougang Research Institute of Technology, 100043 Beijing, PR China

^* email: lzwbeijing2007@163.com

Received: 12 January 2018
Accepted: 7 June 2018

Abstract

The relationship between fish-scaling resistance of ultra-low carbon (ULC) enamel steel and continuous annealing soaking temperature was rarely studied before. In this paper, the influence of continuous annealing soaking temperature on microstructure, precipitation behavior and fish-scaling resistance of ULC steel for porcelain enameling was investigated. The results obtained were as follows: for ULC enamel steel, with the continuous annealing soaking temperature increasing from 750 °C to 840 °C, the mean diameter of second phase particle increased from 41 nm to 52 nm, the corresponding volume fraction decreased from 5.8 × 10⁻³ m³/m³ to 2.9 × 10⁻³ m³/m³, and the ferrite grain size grew from 13.4 µm up to 17.3 µm, the hydrogen permeation value (TH value) decreased from 32 min/mm² to 12 min/mm². The grain boundary and precipitates are main hydrogen traps, as the ferrite grain size increased and the volume fraction of second phase particles decreased, the fish-scaling resistance of ULC enamel steel decreased.