Effects of Cooling Rate during Quenching and Tempering Conditions on Microstructures and Mechanical Properties of Carbon Steel Flange

Abstract

This study investigated the mechanical properties of steel in flanges, with the goal of obtaining high strength and high toughness. Quenching was applied alone or in combination with tempering at one of nine combinations of three temperatures TTEM and durations tTEM. Cooling rates at various flange locations during quenching were first estimated using finite element method simulation, and the three locations were selected for mechanical testing in terms of cooling rate. Microstructures of specimens were observed at each condition. Tensile test and hardness test were performed at room temperature, and a Charpy impact test was performed at −46 °C. All specimens had a multiphase microstructure composed of matrix and secondary phases, which decomposed under the various tempering conditions. Decrease in cooling rate (CR) during quenching caused reduction in hardness and strength but did not affect low-temperature toughness significantly. After tempering, hardness and strength were reduced and low-temperature toughness was increased. Microstructures and mechanical properties under the various tempering conditions and CRs during quenching were discussed. This work was based on the properties directly obtained from flanges under industrial processes and is thus expected to be useful for practical applications.

Effect Nickel and Quench-Temper Process on Mechanical and Corrosion Properties of Astm A588 Waethering Steel

“…The tempered martensite, which consists of recrystallization ferrite (equiaxed α phase) and cementite phase, is formed as a result of singlephase martensite (BCT-body centered tetragonal) saturated with carbon undergoing a reaction due to low energy activation for diffusion during reheating process [16]- [17]. As a result of the tempered martensite formation, the mechanical properties are not as hard as martensite but more Effect of Nickel Addition and Quench-Temper Process on .../ Miftakhur Rohmah | 91 ductile than martensite [17]. As tempered at 400 ℃, the ferrite increases due to the reduction in the martensite phase and facilitates the fine pearlite precipitation.…”

Effect of Cooling Rate on Microstructure and Mechanical Properties According to Heat Treatment Temperature of Inconel 625

“…in order to be applied to piping systems in extreme environments, forged flanges manufactured by hot forging are mainly used and have the advantage of obtaining excellent mechanical properties such as high strength and ductility [3][4]. however, when manufacturing a hot forged flange with a thick and complex shape, the cooling rate varies depending on the location due to the difference in thermal gradient during the cooling process after hot forging [5][6]. Therefore, the difference in thermal gradient acts as one of the main factors that generate thermal deformation and thermal stress, resulting in the difference in microstructure and mechanical properties.…”

Enhancing S45C steel for the primary component of an automatic coupler using quench-tempering techniques

“…Akhyar [21] researched the effects of heat treatment and microstructure on S45C steel. Haeju [22] investigated the mechanical properties of steel to obtain high strength and toughness by using heat treatment in the form of quench and tempering. Vieira [11] conducted quenching research using aqueous polymer solutions to increase hardness and mechanical strength.…”