Effect of Al2O3 Addition on Mineralogical Modification and Crystallization Kinetics of a High Basicity BOF Steel Slag

Metallurgical and Materials Transactions B - Basic oxygen furnace (BOF) steel slag is a main byproduct that is produced during the converter steelmaking process. The volume instability and fast...     

Observation of calcium aluminate inclusions at interfaces between Ca-treated,Al-killed steels and slags

The evolution of Al₂O₃-CaO inclusions on molten steel surfaces and at molten steel/slag interfaces was observed in-situ through a confocal scanning laser microscope (CSLM) equipped with a gold-image furnace. Depending on the slag chemistry, some of the initially liquid inclusions evolved into irregular Al₂O₃ or SiO₂-enriched inclusions during the separation across the interface. Inclusions were found to cluster at specific locations at the steel/slag interface. Unlike capillary-depression-driven clustering, which is observed on molten steel surfaces, a weak repulsive force opposes fluid-flow-driven clustering at the steel/slag interface. After clustering, the irregular solid inclusions were observed to agglomerate to form large aggregates. This article is based on a presentation given in the Mills Symposium entitled “Metals, Slags, Glasses: High Temperature Properties & Phenomena,” which took place at The Institute of Materials in London, England, on August 22–23, 2002.     

Optimization of Mineralogy and Microstructure of Solidified Basic Oxygen Furnace Slag Through SiO2 Addition or Atmosphere Control During Hot-Stage Slag Treatment

Metallurgical and Materials Transactions B - Valorization of basic oxygen furnace (BOF) slag is of significant importance for mitigation of the steel production’s environmental impact. The...     

Investigation of Origin of Attached Cu-Ag Droplets to Solid Particles During High-Temperature Slag/Copper/Spinel Interactions

Metallurgical and Materials Transactions B - This study investigates the origin of mechanically entrained metal droplets in liquid slag due to their interaction with solid spinel particles. Two...     

Influence of FeO/SiO2 and CaO/SiO2 Ratios in Iron‐Saturated ZnO‐Rich Fayalite Slags on the Corrosion of MgO

The corrosion behavior of MgO in iron‐saturated ZnO‐rich fayalite (ZFS) slags having various FeO/SiO₂ ratio and CaO/SiO₂ ratio was investigated using MgO crucible tests for 12 h at 1200°C. The FeO/SiO₂ and CaO/SiO₂ ratios in the ZFS slags were varied from 1.0 to 2.2, and from 0.04 to 0.32, respectively. In all of the tests, it was observed that MgO dissolves into ZFS slags and that (Zn,Fe,Mg)₂SiO₄ olivine and (Zn,Fe,Mg)O solid solution are formed at the crucible/slag interface. The MgO dissolution decreased with the FeO/SiO₂ ratio up to a value of 1.7 and then slightly increased, whereas it continuously increased with the CaO/SiO₂ ratio. There is no obvious relationship between the amount of olivine and the FeO/SiO₂ ratio or CaO/SiO₂ ratio. In comparison, the formation of (Zn,Fe,Mg)O solid solution is enhanced by increasing the FeO/SiO₂ ratio or CaO/SiO₂ ratio in ZFS slags. The results suggest that MgO corrosion is the lowest for FeO/SiO₂ and CaO/SiO₂ ratios around 1.7 and 0, respectively.     

Semi-Markovian approach for modelling seismic aftershocks

In this paper, we present an approach, based on a Markov process, for modelling earthquake aftershocks. From our earthquake aftershock swarm files, we first show our preliminary observations on the phenomenon. Then we present the theoretical basis of a semi-Markovian approach and develop a parametric study of the proposed model. Finally, we discuss the results obtained to date, together with possible improvements of the model.     

Tribological behaviour and internal stress of diamond coating deposited with a stationary d.c. plasma jet

A diamond coating was produced by a stationary d.c. plasma jet in a confined circular area. Using scanning electron microscopy, optical microscopy, laser profilometry and Raman spectroscopy, it was found that the diamond coated area is inhomogeneous with respect to morphology, purity, thickness, and internal stress. Surrounding the diamond coated central area, an amorphous carbon rich area was identified. The morphologically distinct regions were evaluated separately in a fretting wear test against a corundum counterbody. The frictional behaviour was observed to be dependent on the morphology and structure of the coating and the diamond crystal size and orientation in the diamond coated area. No evidence of any fretting wear damage was found in the diamond coated area, whereas a lot of fretting induced scratches were observed in the amorphous carbon rich area. The presence of wear debris was clearly observed in the fretting contacts both inside and outside the diamond coated area.