Crack Phenomena in Heat Treatment Process in AISI 1015 and AISI 4340

• Main Author: KRISMANTO SIPAYUNG (NIM 13704019), EDY
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/10307
• Institution: Institut Teknologi Bandung

This final Project was carried out to study the crack occured due to heat treatment. Due to this heat treatment, the properties of material may change into hardening or softening. This properties can be obtained depend on the objective of heat treatment process. However, heat treatment process may also cause the defects, such as oxidation, decarburization, soft spot, crack or distortion. Therefore it is necessary to find the effect of heat treatment process to cracking.<p>In this experiment, material made from scrab was subjected to heating process which consisted of two kind of steels with different alloy, and made with the different thickness and the form of rectangular. Heating treatment was carried out up to austenite temperature, followed by slowly cooling treatment in the furnace, and then reheated until austenite temperature and followed by quenching. Observation was observed crack by microscope, hardness test, and data processing.<p>By heating material up to austenite temperature and followed by quenching will result in residual stress. Residual stress causes by volume expansion and volume contraction when quenching the material. The residual stress depends of alloy and thickness of material. So, Higher alloy and thicker material will result crack. Crack produce was quite big and appeared in only one edge. The higher cooling rate and bigger material will influence the appearance of crack. <br />