Effects of Copper on the Microstructure and Mechanical Properties of Low Temperature Ductile Iron

Author of the article:QI Peng 1 , XU Rongfu 1 , MA Yihao 1 , WANG Wenhao 1 , WANG Guangyu 1 , PEI Dongliang 2 , SIMON Yish

Author's Workplace：1. School of Materials Science and Engineering, Shandong Jianzhu University, Ji'nan 250101, China; 2. Shandong Taikai Precision Casting Co., Ltd., Tai'an 271000, China

Key Words： ferritic ductile iron; copper; mechanical properties; low temperature toughness; low temperature ductile iron

Abstract： At present, increasing attention has been given to the low temperature impact toughness of ductile iron. In this
paper, the effect of copper on the microstructure and mechanical properties of low temperature nodular iron was studied.
The experimental results show that copper can improve the roundness of graphite spheres, reduce the diameter of graphite
spheres and make the distribution of graphite spheres more uniform. In a certain range (mass fraction of copper from
0~0.5%), with increasing copper content, the tensile strength and hardness of ductile iron are effectively improved, while
the low temperature impact performance and elongation are decreased. When the nominal copper content is 0.3%, the
Brinell hardness is 178 HBW, the tensile strength is 510 MPa, the elongation is 18%, and the low temperature impact
energy is 16 J after heat treatment at -40 ℃, showing a preferably the comprehensive performance.