FERRITE-BASED HEAT-RESISTANT STEEL WITH LAVES PHASE DISPERSED AND DEPOSITED FINELY AND PRODUCTION METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a ferrite-based heat-resistant steel, with the fine Laves phase of high number density dispersed.;SOLUTION: A ferrite-based heat-resistant steel which contains 0.2-1.0 mass% of Hf, etc., crystallizes with the δ-ferrite phase as the primary crystal and undergoes decomposition of the δ-ferrite phase into the γ-austenite phase and the Laves phase, during cooling after solidification, and then transformation of the γ-austenite phase into the α-ferrite phase is heated again from room temperature to a temperature range corresponding to the δ single-phase region and cooled continuously to the (α+Laves) two-phase at cooling rate of 1°C/s to 100°C/s so as to cause fine Laves particles to be dispersed in the ferrite host phase in a point/row distribution form.;COPYRIGHT: (C)2014,JPO&INPIT