Flame Straightening of ASTM A36 Steel: A Study on Mechanical and Microstructural Properties Evolution

Firman A. Nugroho; Alif Fadilla Dinandaka; Muhammad Arif Budiyanto; Farhan Primatondi Harahap

Authors

Firman A. Nugroho Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, 16424, Depok, Indonesia
Alif Fadilla Dinandaka Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, 16424, Depok, Indonesia
Muhammad Arif Budiyanto Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, 16424, Depok, Indonesia
Farhan Primatondi Harahap Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, 16424, Depok, Indonesia

Keywords:

Mechanical Properties, Low Carbon Steel, Flame Straightening, Heat Treatment, Hardness, Scanning Electron Microscopy, Microstructural

Abstract

Flame straightening is widely employed in shipbuilding and metal fabrication to correct structural distortions caused by welding and other thermal processes. However, its effects on commonly used structural carbon steels, such as ASTM A36, may influence material performance. This study examines the impact of controlled flame straightening on the mechanical and microstructural properties of ASTM A36 steel. Experimental heat treatments were conducted using an oxy-acetylene torch, followed by hardness and tensile testing, as well as microstructural characterization through Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The results indicate that flame straightening modifies the mechanical behavior of ASTM A36: short-duration heating enhances hardness and yield strength, whereas prolonged exposure causes microstructural softening due to grain coarsening and oxidation, ultimately reducing mechanical strength.