اميرارسلان ساحلي فر

The aim of this research is to investigate the effect of carbon equivalent and diameter of rebars produced by Thermex method on the workability and mechanical behavior of St-5Sp structural steel. The Thermex process is a modern meth-od of rebar production where the product is quenched by passing through a cooling medium for a short time and then tempered. Chemical composition is one of the effective factors in the mechanical behavior of continuous casting billets. Also, due to the difference in phases from the core and surface of the rebar, the difference in mechanical properties is evident in different parts of the cross-section. Carbon equivalent was used as a key indicator for predicting mechanical behavior. For this purpose, chemical composition analysis, microstructural observations, and EDS analysis of non-metallic inclusions were employed. The mechanical properties of samples were eva‎luated through tensile tests at room temperature and hot compression testing of billets with variable carbon equivalent of 0.37-0.48 in the range of 950-1150°C at strain rate of 0.1s⁻¹. Increasing the carbon equivalent to 0.48 resulted in an increase in ultimate strength from 512 to 559 MPa and a 10% reduction in ductility. At 1050°C, the billet with carbon equivalent of 0.48 with peak stress of 59.5 MPa and softening rate of 15% leads to favorable dynamic recrystallization. Additionally, dilatometry analysis was performed to investigate the effect of carbon equivalent on critical phase transformation temperatures. With increasing carbon equivalent to 0.48, the austenite phase transformation temperature decreases to 802°C.

كربن معادل , شمش ريخته گري پيوسته , ميلگرد ترمكس , خواص مكانيكي

Carbon equivalent , ,Continuous cast billet , THERMEX reinforcing bar , Mechanical properties , Microstructure

Amirarsalan Sahelifar

Dr. Hamidreza Jafarian - Dr. Alireza Ivani