TITLE:
Effect of Heat Treatment on Fe–0.3%P–0.14%C Alloy
AUTHORS:
Yashwant Mehta, K. Chandra, Rajinder Ambardar, P. S. Mishra
KEYWORDS:
Phosphoric Iron, Microhardness, Microstructure, Heat treatment.
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.9 No.9,
September
20,
2010
ABSTRACT: Modern iron and steel industry is based on the iron – carbon diagram. However, a major
problem associated with Fe-C alloys is that they corrode and cause losses to the tune
of 5% of GDP to the world. Ancient Indian iron (Fe-P-C) artifacts like the Delhi Iron
Pillar have withstood atmospheric corrosion for about 1600 years. Phosphorous and carbon
are used as the alloying elements for strengthening iron and imparting corrosion resistance
to it. Therefore, there is a need to understand the Iron-Phosphorous-Carbon alloy system and
to develop strong and corrosion resistant, iron products. In the present study, Fe-0.3%P-
0.14%C alloy is subjected to heat treatment schedule by varying the rate of cooling after 30
minutes of heating at 800℃. Microstructural characterization is carried out on the heat
treatment samples. The studies reveal a higher concentration of carbides in the form of
pearlite formed at the grain boundaries of the ferrite grains in the air cooled samples. As per
the literature, carbon pushes phosphorous from the grain boundaries to the grain interior by
site competition. Micro-hardness studies on the test samples indicate that hardness of the
phases formed at the grain boundaries is higher as compared to the hardness of the interior
of the ferritic grains.