Perpustakaan Digital ITB

Steel is a metal with a wide range of applications and variations. From daily home appliances into airplane spare parts cannot be separated from steel. One type of steel is medium carbon steel. This steel has 0.3-0.6 % carbon, which has good mechanical properties and its performance can be increased by heat treatment. One of medium carbon steel that is widely used in airplanes, manufacturing industries, and defense industry is AISI 4340 steel series. AISI 4340 steel series has good toughness and its mechanical properties will improve significantly with proper heat treatments. Common heat treatment such as conventional heat treatment is not enough to increase the strength of AISI 4340. Nowadays, a lot of manufacturing companies use induction heating to heat the specimen. Induction heating dispenses rapid, contactless, and efficient heating of conductive materials such as steel. This study will investigate the effect of rapid heating using induction heating on the austenitization temperature, microstructure, and mechanical properties of AISI 4340. First, an assortment of published research papers, books and other sources of information related to rapid heating rate, heat treatment, induction heating, and AISI 4340 steel. Other supporting information for the author also gathered. Next, irrelevant research result is eliminated. Then, discussion and analysis of collected information done to answer the literature review objective. The analysis will provide an understanding of the rapid heating effect on microstructural evolution and mechanical properties of AISI 4340 steel. Finally, the conclusion and suggestion were obtained from the conducted literature review. The rapid heat treatment of AISI 4340 steel will result in a slight grain refinement on the final microstructure of as-received specimens due to the site for austenite nucleation is limited. A finer grain size will be obtained if the prior microstructural effect of the specimen is eliminated by pre-treatment such as conventional heat treatment quenching (CHQ), spheroidizing, and cold working. By eliminating the prior microstructural effect, multiple nucleation sites will be formed which results in finer grain size. The mechanical properties of the treated specimens show an increase in yield strength and tensile strength but slightly decrease the total elongation. The improvement in strength is due to the finer grain of the observed specimen and other possibilities, for example, an increase in the fraction of martensite and bainite and an increase in pearlite fraction followed by the decrease in ferrite fraction. Rapid heating of AISI 4340 also increases the austenitization critical temperature, in other words, the higher temperature is required for the austenite nucleation.