Effect of carbon content on the heat treatment process

• Main Author: Ng, Wei Joo.
• Other Authors: Oh Joo Tien
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/44775
• Institution: Nanyang Technological University

This Final Year Project shows the effect of carbon content on the heat treatment process; and how the interlamellar spacing differs under prolong heat treatment with different carbon compositions. The purpose of the project is to investigate the relation and effects between the different carbon content and heat treatment time on the interlamellar spacing. Microstructures images were obtained by using the Scanning Electron Microscope (SEM) and the lamellar spacing were measured using software called ImageJ 1.37v. For this project, two different compositions of steel specimens were used, 0.77% and 1%, whereby both were heat treated at the temperatures of 0, 4, 8, 16, 24 and 48 hours. A series of measurements were collected to determine the average spacing of the interlamellar spacing. Charts were plotted to evaluate pearlite structure at different heat treatment hours. From the results and analysis, it is observed that under extended heat treatment, the cementite plates will form globules of spheroids. Fine pearlite structures are found to have smaller interlamellar spacing. Pearlite tends to coarsen in the high carbon content steel. Hence, steel that has lower carbon content (0.77%C) has a faster spheroidization rate. The interlamellar spacing for this steel is also larger than the higher carbon content steel (1%C).