#TITLE_ALTERNATIVE#

• Main Author: FIRMANSYAH AHER (NIM 13703007), DION
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/10256
• Institution: Institut Teknologi Bandung

Bar Chain Conveyor is one of the mechanical devices that convey materials, packages, and items from one place to another using chain as the conveying element. The material of the chain is AISI 4142 steel and should has good properties; such as fatigue resistance, wear resistance, and corrosion resistance. Spheroidizing process is one of the methods to obtain a steel with a good combination of these properties.<p>This research will examine the effect of spheroidizing on microstructure and mechanical properties of AISI 4142 steel. Spheroidizing is conducted by heating the samples to a temperature below low critical temperature (LCT) of steels and holding them for 5, 10, 15, 20, 25, and 48 hours, followed by furnace cooling. The experiments will also examine the effect of initial phases on the spheroidizing rate. The initial phases are virgin martensite, lower bainite, and tempered martensite.<p>The microstructure after spheroidizing process has changed from the initial microstructure into two phases, ferrite and spheroid carbide particles. A spheroidized structure is the most stable microstructure that had ever been found in steel. As spheroidizing being applied, both ferrite and carbide particles will have a tendency to change into equiaxed and spheroidized grain respectively. These changes are due to recovery and followed by coarsening mechanism. Spheroidizing at 700oC for 48 hours has decreased the hardness of material from 285 HV0,2 to 201 HV0,2 , decreases the tensile strength from ou = 832 MPa to ou = 688 MPa, decreases yield strength from oy = 688 MPa to oy = 555 MPa. However, the elongation was increased from 17% to 26,8%. <br />