Pengaruh kadar karbon terhadap sifat mekanik dan mikrostruktur baja tulangan

Abstract

Most of the local reinforcing steel is produced from scrap materials because it is more profitable. Using scrap as raw material for rebar production by steel mills will more or less adversely affect the quality of the rebar. This study aims to analyze the carbon content and level of compliance with standards of four brands of reinforcing steel produced by local manufacturers. 16 mm diameter rebar steel was tested for chemical content (carbon content) using Scanning Electron Microscope-Energy Dispersion Spectroscopy (SEM-EDX) test. While the mechanical properties were tested with a Universal Testing Machine (UTM). The carbon content of the test results are S2 = 4,94%wt; S4 = 8,51%wt; S7 = 5,99%wt; and S8 = 3,79%wt. All brands of reinforcing steel do not meet the carbon requirements according to SNI 2052: 2017 specifications. Although the carbon content in these four samples is relatively high, the tensile test results of the reinforcing steel show ductile behavior. Ratio of Ultimate Tensile Strength (UTS) to Yield Strength (YS) is on average greater than 1.25. And effect of carbon content on microstructure shows that carbon content determines the proportion of ferrite-pellite, the higher the carbon, the higher the proportion of pearlite and the distribution of carbon will affect the homogeneity of the structure.