978-602-70570-4-3 © 2016 Published by ITP PRESS DOI 10.21063/ICTIS.2016.1004 22 International Conference on Technology, Innovation, and Society (ICTIS) 2016 Influence of Cu Addition on Microstructure and Strength of Low Carbon Steel Nofriady. Handra*, Ismet Eka Putra Department of Mechanical Engineering, Institut Teknologi Padang, Indonesia Abstract This study aim is to determine the influence of Cu addition on microstructure and strength of low carbon steel. 0.1% C steel, which contained Cu were used as specimens. The temperatures for heat treatment were determined using a software. The type of specimens was heat treated at specific temperatures in order to obtain 20% and 80% of martensite. Specimens were austenised at 1000 °C for 30 second and followed by water quenching to obtain martensitic structure. The base steel used as the base metal as specimen. The hardness increases with increasing temperature for both of steels. It is found that the hardness, yield strength and ultimate tensile strength of Cu was higher than Base steel. Changes of hardness of annealed samples almost the same in both steels. On the other hand, it is found that addition of Cu can improve tensile strength, total elongation and strength-ductility balance of the steel although no significant effect on yield stress and uniform elongation. Total elongation for Cu steel is 19%, and base steel the elongation values are 15% respectively. Although the martensite content is the same. Total hardness for Cu steel is 390 Hv and 281.8 Hv. However, the Cu steel has the highest hardness than base steel. Therefore, the addition of Cu will increase the hardness, strength and elongation of steel. Keywords: microstructure; hardness; strength; Cu and low carbon steel. Correspondence should be addressed to nof.hand11@gmail.com Copyright © 2016. This is an open access article distributed under the Creative Commons Attribution License. Available online at http://eproceeding.itp.ac.id/ INTRODUCTION The steel and specially to the dual phase steel are becoming more important in the automotive industry, where the high strength and high ductility permit weight reduction without sacrificing formability and low carbon. Dual phase steels derive their characteristic properties from the presence of martensite and austenite islands dispersed in a ferrite matrix [1]. One way of achieving these microstructure is by heating the steels into the intercritical region, which is between the A1 and A3 critical temperature. Dual phase steel, whose microstructure consists mainly of ferrite and martensite, are an excellent choice for applications where low yield strength, high tensile strength, continuous yielding and good uniform elongation are required [2,7]. These steel are produced by annealing plain and low-alloy steel in ferrite-austenite (α – γ) region and cooling below the martensite start temperature at suitable rate [1]. Many researchers have been working on the dual phase steel to determine relationship between microstructure and mechanical properties and to develop new material for specific application. Fe-Cu-C is the most common alloy system used in press and sinter powder metallurgy. This system has many advantages including excellent mechanical properties, sinterability, and competitive cost. However, as end customers continue to require tighter dimensional control of finished parts this alloy is at a disadvantage due to its inherent dimensional variability. Changing the method of copper addition influences the dimensional stability of this system. This work studies the mechanical, dimensional, and microstructural differences of sintered Fe-