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This paper reveals an appropriate ingredient to operating the hazardous and radioactive electric arc furnace dust (EAFD) from the steel production factory using the cement immobilization technique. The cement specimens were prepared by mixing tap water with the binders (i.e., ordinary Portland cement: OPC, and the EAFD) at the different EAFD replacement of 0%, 15%, 25%, 35%, 40%, 45%, and 50% by weight. The water-to-binders ratio was fi xed at 0.40. The compressive strength test on the fabricated samples was performed at two different curing times of 14 and 28 days. It was found that the highest compressive strength of the samples can be obtained when the EAFD loading was 25%. However, the compressive strength criteria for the cement waste form, the use of the ingredient with the higher EAFD loading (35% EAFD with 28-day curing time) for the immobilization is favorable while meets the criteria. The phase composition and microstructure morphology of all samples were analyzed by X-ray diffraction (XRD), X-ray fl uorescence (XRF) and scanning electron microscopy (SEM-EDS).

Abstract. The hot deformation behavior of HSLA steel was investigated by using a MMS-200 thermal mechanical machine at different conditions and with deformation temperature of 800-1100 o C and strain rate of 0.1-10 S -1 . FEM was analyzed the deformation characteristics of hot compression through Deform-3D software. It was discovered that the flow stress increases with increasing strain rate and decreasing temperature. The activation energy and stress exponent during hot deformation were calculated using hyperbolic sine constitutive equations. The result from the experiment represents the activation energy and stress exponent during hot compression of 222.256 kJ/mol. and 10.84. The prediction of distribution stress values from the constitutive equation in Deform-3D can be matched with the experimental results. IntroductionHigh strength low alloy steel (HSLA) is a type of steel widely used for structural construction. Steels with low carbon content and very small additions of strong carbide or carbonitride forming elements such as Nb, V, and Ti to strengthening precipitation and grain refinement are called microalloyed or high strength low alloy steel [1]. These steels are much stronger and tougher than ordinary carbon steels, more ductile, highly formable, weldable and highly resistant to corrosion. Nowadays, HSLA steel has been improved with suitable chemical composition and thermo mechanical treatment in order to reinforce its application in heavy industries and automotive. Recently, HSLA steel has been investigated for several features, including its hot deformation behaviors. Hot deformation process is necessary to improve the effectiveness of HSLA steel. With the increasing use of FEM (finite element method) to simulate the specimen behavior under the various parameter of compression test. The relationships between the constitutive equation and the relating process variables such as strain rate and temperature to the flow stress of the deforming material is required, and it is important to calculate the flow stress [2]. Flow stress can be defined as the resistance of a material against plastic deformation and it is expressed as a function of temperature, strain, and strain rate. Hence, FEM technique provides an effective approach for evaluating and determining the distribution and variation of thermo mechanical parameters in deformed specimens during hot working [3,4]. In this paper, the influence of characteristic hot deformation behavior of HSLA steel during compression test at different temperature and strain rate will be investigated. The general constitutive equations were used to determine the hot deformation constants of the material from experimental

The hot deformation behavior and corrosion properties of HSLA steels under compression processes were studied. In this paper, the hot compression tests were conducted at a deformation temperature of 800 and 1100°C with strain rates of 0.1, 1 and 10 s -1 using an MMS-200 thermal-mechanical simulator. The true stress-strain curves under different conditions were obtained. The flow stress increases with the increase of strain rate and decreasing deformation temperature. The microstructure, hardness, and electrochemical properties of the specimens were investigated to discover/understand the effect of the deformation temperature on specimens. Microstructure observation shows that the grain size increased with an increase of deformation temperature, and fine AF grains were observed in specimens, which had direct effects on the resulting hardness, leading to the highest hardness values. From the final, optimized hot deformation process, the specimens deformed at the temperature of 800°C and the strain rate of 0.1 s -1 had a completely recrystallized and homogeneous grain structure and could be improved by corrosion resistance better than the as-cast specimens.

In this study, the two types of high-strength low-alloy steels were melted and cast in a vacuum induction furnace. Phase transition temperature of HSLA steel was calculated by JMatPro software. The calculation results show that the two different types of HSLA steels which have equal phase proportions of ferrite and austenite at a temperature of approximately 820 and 800 °C in HSLA-I and HSLA-II, respectively. In addition, the effect of chemical composition on the microstructure and mechanical properties of steels were studied. The results indicate that the ultimate tensile stress value of HSLA-II samples was greater than the HSLA-I samples by about 35%, and the yield stress and breaking strength value of HSLA-II were higher than HSLA-I as well.

Activated carbons (ACs) are a versatile group of adsorbents for water pollution control, especially organic dyes. Harsh chemicals and high temperatures are required for the activation process of ACs, which becomes a significant concern due to their toxicity and harmful effects on human health and the environment. Gamma irradiation, an alternative green technique, is a promising strategy for pretreatment and escalates the nitrogen or oxygen functional group of ACs. The current study provides the modification of ACs by the gamma irradiation in the various pH (5-11) of urea solution. The modified ACs were characterized by scanning electron microscopy (SEM), nitrogen gas adsorption-desorption analysts (BET), temperature program desorption (TPD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and X-ray diffraction spectroscopy (XRD). The point of zero charges and dye adsorption capacities were determined. This finding demonstrates that the ACs can be modified by gamma irradiation at 25 kGy in the urea solution media. The degree of graphitization enhanced significantly at pH 11(AC-pH11). The oxygen-rich functional groups created by radiation assists could enhance the electrostatic attraction between acid gases or cationic dyes. AC-pH11 also was able to adsorb methylene blue (160.73 ± 1.70 mg/g) greater than methyl orange (127.57 ± 2.22 mg/g).