Study of the effects of heat treatment on reinforcing bars Which is produced by the Libyan Iron and Steel Company

Abstract

This research paper aims to study the effects of heat treatment on 14 mm reinforcing bars that are produced by the Libyan Iron and Steel Company. These operations were conducted in the quality control laboratory, and it was found that there are two types of 14 mm reinforcing bars: (G-40) and (G- 60). The difference between them is the percentage of carbon present in their chemical composition, as the percentage of carbon in the variety (G-40) ranges between 0.25% and 0.38%, and as for the variety (G-60), it ranges between 0.35% and 0.45%[1]. In this research paper, three different heat treatment processes were carried out: hardening, neutralization and fermentation at a constant temperature of 850°C and for a constant period of 30 minutes on 14 mm reinforcement bars with American specifications (ASTM A615 G-40 and G-60)[5]. After performing these operations, a change occurred in the internal structure of the material and its phases, which led to a change in the mechanical properties of these bars. To know and determine this change, mechanical tests (tensile test and hardness test) and microscopic examination were performed.