Determination of the critical points in solid-state phase transformation of some hypoeutectoid steels

Constantin Dulucheanu,Traian Lucian Severin,Alexandru Potorac,Luminita Irimescu,R.K Agarwal

doi:10.1051/e3sconf/20199504004

Constantin Dulucheanu, Traian Lucian Severin + Show 3 more

Open Access

https://doi.org/10.1051/e3sconf/20199504004

Copy DOI

Abstract

This study allowed, by dilatometric analyses, both to highlight the solid state transformations that occurred during the continuous heating of two hypoeutectoid steels, as well as to investigate the effect of the heating rate on the critical points at which these transformations occurred. The eutectoid transformation (the pearlite dissolution into austenite) was carried out in a temperatures interval, ranging between pearlite dissolution start temperature (Ac1) and pearlite dissolution finish temperature (denoted Acfp in this article). Increasing the heating rate determined a displacement of the critical points in solid-state phase transformation to higher temperatures; these displacements were more significant for the Acfp point, than for the critical points Ac1 and Ac3.

Highlights

Nodifference between the pearlite dissolution process (P A) and the allotropic transformation of ferrite into austenite (F A) is detected on the continuous heating dilatometric curve obtained for a hypoeutectoid Fe-C binary alloy [4, 5]; all the dilatometric curves drawn for the A_Steel and B_Steel present an unusual anomaly at the onset of the austenitization
Dilatometric analyses performed on a DIL 402 ExpedisSUPREME dilatometer, allowed to highlight the solidstate phase transformations that occurred during the continuous heating of two hypoeutectoid steels, with 0.087% C and 0.511% Mn, respectively with 0.093% C and 1.922% Mn, as well as to determine the critical temperatures at which these transformations occurred
The pearlite dissolution into austenite was carried out in a temperature interval ranging between pearlite dissolution start temperature and pearlite dissolution finish temperature

Summary

Introduction

This article describes some of the researches carried out at University "Stefan cel Mare" of Suceava, Romania, in order to obtain and characterise dual-phase steels; the. As a result of these researches, the temperatures of the critical points in solid-state phase transformation were identified and the influence of the heating rate on these temperatures was established

Experimental details

Results and discussion

Conclusions