Effect of Low Temperature Heat Treatment on Different Original Graphite Microstructures of Nodular Cast Iron

Yan Zhao

doi:10.19026/rjaset.6.3748

Abstract

To understand the effect of low temperature heat treatment on microstructure of nodular graphite, nodular cast irons with the same chemical composition but different microstructure were made by the heredity of raw materials. The effects of low temperature heat treatment on the different microstructures of graphite were studied. The results show that after the low temperature treatment, the modularization rate and level are improved observably for as-cast graphite with lower degree of graphitization and worse effect of nodularization and the mean sphere diameter of the graphite increases; the spot graphite arises for as-cast graphite with higher degree of graphitization and better effect of nodularization, the mean sphere diameter of the graphite decreases, the spot and nodular graphite distribute alternately, the spheroidization grade and nodularization rate do not change obviously.

Highlights

With the advent of nodular graphite cast iron since 1940s, it has been widely used in mechanical engineering and other fields due to its predominant performance and lower production cost
In order to improve the microstructure and performance of nodular graphite cast iron further, scientific researchers have been limited to the research areas of casting process and material optimization, and the effect of heat treatment, especially the low temperature heat treatment has attached a lot of academic attention increasingly by virtue of its low energy consumption and low cost (Hao, 2004)
In order to get a comprehensive understanding of the effect of low temperature heat treatment on microstructure of nodular graphite, at the same time considering reducing the energy consumption and production cost

Summary

INTRODUCTION

With the advent of nodular graphite cast iron since 1940s, it has been widely used in mechanical engineering and other fields due to its predominant performance and lower production cost. In order to improve the microstructure and performance of nodular graphite cast iron further, scientific researchers have been limited to the research areas of casting process and material optimization, and the effect of heat treatment, especially the low temperature heat treatment has attached a lot of academic attention increasingly by virtue of its low energy consumption and low cost (Hao, 2004). The principal factors those affect the microstructure and performance of nodular graphite cast iron are microstructure of matrix, graphite’s shape, size, quantity, distribution and so on (Gülcan et al, 2006; Zhao et al, 2004; Torsten and Ingvar, 2007; Nuno et al, 2008; Hao and Yang, 2008). The effects of low temperature heat treatment on different original graphite structures of nodular graphite cast irons are studied in this study

METHODOLOGY

RESULTS AND DISCUSSION

CONCLUSION