Ameer K Ibraheem

Intertek · Production & Integrity Assurance

Small ingots of 0.1%C, 1.4%Mn, 0.04%Nb steel were cast in a hot ceramic mould in which solidification and cooling rate simulated thin slab casting. The just-cast austenite was direct rolled in three passes from an initial thickness of 15mm to 3.6 mm. ln a series of experiments,‎ first passes were applied in the temperature range 1200-1120°C, secon...

The direct rolling of just-cast austenite of low carbon steel improves the economics of steel making, but the microstructure of the austenite prior to the commencement of rolling is different from that of reheated austenite. In the cases of low carbon steel microalloyed singly with Nb or Ti it has been previously shown that the just-cast austenite...

The constitution of austenite in thin-slab cast, low-C, Mn steel microalloyed with 0. 007wt% Ti, 0.04wt%Nb and O.Ollwt%V was simulated in small, laboratory castings . Two carbon levels, 0.007wt% and 0.22wt%C, each at two nitrogen levels, 0.003wt% and - 0.013wt%N, were investigated. After solidification the castings were quenched rapidly from - 1400...

The potential of three novel processing routes for producing ultrafine ferrite in steel has been investigated. Transformational grain refinement (TGR) from a refined austenite grain size, using heavy, single pass rolling reductions above the Ar3 temperature produced submicrometre grains in surface layers and 1·5 µm grains in the centre of 2–3·5 mm...

The phenomenon of ultra grain refinement of ferrite in surface layers of hot rolled strip has been studied in a low carbon, niobium microalloyed steel. Wedge specimens were used, to vary the nominal equivalent strain applied during rolling from zero to approximately unity, and the cooling rate after rolling was varied from ~ 20 to 1 K s -1. In cont...

The objective of this study was to assess the chemical safety awareness for undergraduate analytical chemistry students. Data were collected from years one (First year) and four (final year) students in February 2018 using structured questionnaires (Multiple choices) designed for this purpose with chemical safety in mind, e.g. hazard warning symbol...

Microbiologically Induced Corrosion (MIC) is the deterioration of a metal by corrosion processes that occurs directly or indirectly because of the metabolic activity of microorganisms in cold water systems. This type of corrosion results in severe pitting of metals, leading to rapid failures. The type of bacteria that cause this type of corrosion a...

The production of functional tool steel components by selective laser sintering requires an understanding of the effects of the laser processing parameters on the microstructure evolution during the fabrication process. This would allow the production of tools that have predictable and reproducible microstructure, good mechanical properties and low...

The attainment of ultrafine ferrite grain structures in low carbon, low alloy steels is of interest because of the improvement in yield strength and Charpy impact transition temperature predicted by extrapolation of known data to very fine grain sizes. This paper presents a summary of research aimed at producing ultrafine ferrite in a niobium micro...

The attainment of ever finer ferrite grain structures in low carbon, low alloy steels is of interest because significantly higher yield strengths and lower ductile/brittle transition temperatures are predicted at ultra-fine grain sizes. The limit to which ferrite can be refined by conventional thermomechanical processing of austenite is about 4 mic...

The potential of three novel processing routes for producing ultra-fine ferrite in steel has been investigated. Transformational grain refinement (TGR) from a refined austenite grain size, using heavy, single-pass rolling reductions above the Ar3 produced sub-µm grains in surface layers and 1.5 µm grains in the centre of 2-3.5 mm thick plates of a...

Ingots of low carbon steels with additions of Nb, V and Ti were made in a manner that simulated thin slab casting, and were hot direct rolled. Mn and Si contents were kept constant at 1.4 wt% and 0.25 wt% respectively. Carbon contents were varied from 0.04-0.88 wt%, vanadium from 0.02-0.09 wt% and titanium from 0.007-0.025. The niobium content was...

Low carbon Ti-Nb steels were reheated to temperatures up to 1400 deg C, and either quenched or slowly cooled. Previously hot rolled material and as-cast material were investigated. (TiN)-rich cubes and laths present at the reheating temperature had distinctly different Ti contents. Both morphologies were found to be potent nucleation sites for the...

The morphology and chemical compositions of Ti-rich cube and lath precipitates, and of Nb-rich and MnS particles precipitated on them, were investigated in NbTi-microalloyed, low carbon steel. In previously controlled rolled steel, laths were richer in Ti than cubes and both were richer in Ti than predicted by a model of the solution thermodynamics...

The precipitate present in a controlled rolled low carbon Ti-Nb microalloyed steel have been studied on reheating to 850-1400 degC. Below 1100 degC (Nb_rich, Ti) spheres dissolve and coarsen, and spherical caps and nodules of (Nb_rich, Ti) appear on the faces and corners of (Ti_rich, Nb) cubes and laths. AlN coprecipitates with many of the caps and...

A study has been made of the effect of heat treatment on the microstructure and short term mechanical properties of welded Inconel 182. Optical, X-ray and transmission electron microscopy were carried out to study the effects of stress relieving, solution treatment and ageing at temperatures between 400°C and 700°C on the microstructure of the wel...