Abnormal expansion due to pearlite-to-austenite transformation in high aluminium-added steels

Abstract

Addition of alloying elements usually moves eutectoid point to left whilst aluminium enhances eutectoid carbon content. The carbon expands lattice parameters of austenite. High aluminium addition in steels led to volume expansion at pearlite-to-austenite transformation since specific volume of austenite is larger than that of mother phases, which is proposed to determine the volume expansion or contraction. It has been proven by calculations based on thermodynamics as well as accurate experimental observations of dilatometry study.

Keywords:

• Ferrite
• Cementite
• Dilatation curve
• Low density steels

ORCID

H. L. Yi http://orcid.org/0000-0002-2853-2848

Additional information

Funding

The research was financially supported by the National Natural Science Foundation of China (Grant Nos. 51204051 and U1560204).