Technical Note: Investigation and improvement of the resistance against crack propagation for a hot steel rolling tool material

Abstract

Investigations were carried out on the resistance to crack propagation of a tool material for hot steel working. Observations on the tool used on a production line showed that cracks propagate alongside the meshy carbides. A hypothesis was then proposed which stated that crack propagation would be suppressed by changing the carbides into granular shapes. The key to realizing this idea was to heat treat the parent material manufactured by casting, which has never been done in this field. Among the trial and original materials, an appropriate one was selected through laboratory experiments and efficiency was verified on the production line.