Regina, Canada
Regina, Canada

Time filter

Source Type

Mohammadijoo M.,University of Alberta | Collins L.,Evraz Inc. NA | Henein H.,University of Alberta | Ivey D.G.,University of Alberta
International Journal of Advanced Manufacturing Technology | Year: 2017

The addition of a cold wire in conventional tandem submerged arc welding (TSAW), i.e., the CWTSAW process, is proposed to improve the productivity of pipeline manufacturing by increasing welding travel speed and deposition rate, while retaining adequate joint geometry without increasing the welding heat input. In addition to increasing productivity, incorporating a cold wire in the TSAW process improves the fracture toughness by refining the microstructure of the weld heat-affected zone (HAZ). In the present work, the influence of cold-wire addition on the heat input, productivity and properties of an X70 microalloyed steel welded by CWTSAW is investigated. Charpy impact testing and microhardness testing were utilized to investigate the mechanical properties of the HAZ. Scanning electron microscopy (SEM) and tint etching optical microscopy (TEOM) were used to correlate the microstructure alterations with the properties. The low-temperature fracture toughness of the HAZ was improved by 38% when a cold wire was fed at 25.4 cm/min in the conventional TSAW process with a heat input of 22.1 kJ/cm. This improvement was attributed to a reduction in the prior austenite grain (PAG) size and martensite-austenite (M-A) constituent fraction as a result of the reduction in the effective heat input (7.5% reduction) by cold wire addition. The amount of heat input reduction is a function of the cold wire addition rate and the nominal welding heat input. The increase in travel speed and deposition rate of welding by addition of a cold wire at 58 cm/min in the TSAW process with a heat input of 23.2 kJ/cm was 26 and 12%, respectively. © 2017 Springer-Verlag London

Mohammadijoo M.,University of Alberta | Kenny S.,University of Alberta | Kenny S.,Evraz Inc. NA | Collins L.,Evraz Inc. NA | And 2 more authors.
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2017

High-strength low-carbon microalloyed steels may be adversely affected by the high-heat input and thermal cycle that they experience during tandem submerged arc welding. The heat-affected zone (HAZ), particularly the coarse-grained heat-affected zone (CGHAZ), i.e., the region adjacent to the fusion line, has been known to show lower fracture toughness compared with the rest of the steel. The deterioration in toughness of the CGHAZ is attributed to the formation of martensite-austenite (M-A) constituents, local brittle zones, and large prior austenite grains (PAG). In the present work, the influence of the addition of a cold wire at various wire feed rates in cold-wire tandem submerged arc welding, a recently developed welding process for pipeline manufacturing, on the microstructure and mechanical properties of the HAZ of a microalloyed steel has been studied. The cold wire moderates the heat input of welding by consuming the heat of the trail electrode. Macrostructural analysis showed a decrease in the CGHAZ size by addition of a cold wire. Microstructural evaluation, using both tint etching optical microscopy and scanning electron microscopy, indicated the formation of finer PAGs and less fraction of M-A constituents with refined morphology within the CGHAZ when the cold wire was fed at 25.4 cm/min. This resulted in an improvement in the HAZ impact fracture toughness. These improvements are attributed to lower actual heat introduced to the weldment and lower peak temperature in the CGHAZ by cold-wire addition. However, a faster feed rate of the cold wire at 76.2 cm/min adversely affected the toughness due to the formation of slender M-A constituents caused by the relatively faster cooling rate in the CGHAZ. © 2017, The Minerals, Metals & Materials Society and ASM International.

Nafisi S.,EVRAZ INC. NA | Ghomashchi R.,University of Adelaide
Metallography, Microstructure, and Analysis | Year: 2013

Semi-solid metal (SSM) processing is an effective alternative to the classical manufacturing processes of casting and forging. The key issue in SSM is the production of suitable feedstock with guaranteed continuous supply. To produce good quality billets, the current work studied the thixocastability of electromagnetically stirred (EMS) Al-7Si alloy billets and compared them with conventionally cast billets to establish the effect of EMS in improving the quality of feedstock. In all cases, the intention was to study the microstructure of the billets just before feeding it into the high pressure die casting machines and therefore the billets were reheated to thixocasting temperature and isothermally held for 10 min before being quenched in water. The outcome of EMS application was the formation of refined and more globular SSM billet structures with less entrapped eutectic. The implication of pursuing such work is to guarantee continuous supply of feedstock to enable the establishment of manufacturing facilities, similar to mini mills for steel industry, where the feed stock is shipped to casting site to be shaped in high pressure die casting machines. © 2013 Springer Science+Business Media New York and ASM International.

Mohtadi-Bonab M.A.,University of Saskatchewan | Szpunar J.A.,University of Saskatchewan | Collins L.,EVRAZ Inc. NA | Stankievech R.,EVRAZ Inc. NA
International Journal of Hydrogen Energy | Year: 2014

The microstructure of API X70 pipeline steel was modified by applying different heat treatments including water-quenched, water-sprayed, and water-quenched and tempered. Hydrogen induced cracking behavior was investigated on the X70 steel at these heat treatments. Two test methods, Japanese Industrial Standard (JIS) and vacuum thermal desorption, were used to release hydrogen from reversible and irreversible traps. The experimental results showed that the highest amount of discharged hydrogen in reversible and irreversible traps was related to the water-sprayed and as-received steels. The hydrogen discharged content from reversible traps reached to a saturation level after 8 h of charging, and it decreased considerably when the steels were charged for 15 h and 24 h. Hydrogen discharge tests proved that a higher amount of hydrogen inside steel is not a reliable measure for HIC evaluation. HIC test results also document that the water-quenched steel with agglomerated martensite particles had the highest susceptibility to HIC. Texture study results show that a low fraction of important texture components, such as {023}, {321} and {332}, cannot be reliably used to evaluate HIC. As a result, a novel method of manufacturing of pipeline steels with an optimized texture is required to increase safety and reliability of transportation of sour gas and oil. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Calvo J.,McGill University | Collins L.,Formerly IPSCO Research and Development | Collins L.,Evraz Inc. NA | Yue S.,McGill University
ISIJ International | Year: 2010

The hot torsion simulator has been extensively used as a means to understand the microstructure evolution of different steel grades during hot rolling. The test is suitable to simulate 'real' industrial schedules as well as schedules designed to obtain information regarding the intrinsic properties of the materials. For example, it is common to apply 'average' schedules, in which deformation per pass, interpass time, strain rate and cooling rate are kept constant, to determine the characteristic temperatures Ar3, A r1 and Tnr, (start and finish of the austenite transformation and no recrystallization temperatures) of steels. In this work, both a 'real' schedule simulating a rolling schedule in a reversing mill and an 'average' schedule were applied to a series of Ti and Nb microalloyed steels. In general, the steels exhibited somewhat different behaviours for the different thermomechanical schedules, e.g. the pancaking temperature region is easily detectable after an 'average' schedule, while for the 'real' schedule some softening can be detected in the pancaking region, which is strongly dependent on the strain and interpass time. Moreover, the paper analyzes a new approach to stress-strain curves, which is used to better understand the sequence of events which take place during rolling and their dependence on rolling parameters. © 2010 ISIJ.

Abraham S.,Evraz Inc. NA | Chen S.,Evraz Inc. NA
Iron and Steel Technology | Year: 2010

A comprehensive model for recommending the required ladle exit temperatures to achieve consistent superheats in the tundish has been developed. The model is universal and can easily be modified to suit any casting process.

Nafisi S.,EVRAZ INC. NA | Arafin M.A.,McGill University | Collins L.,EVRAZ INC. NA | Szpunar J.,McGill University | Szpunar J.,University of Saskatchewan
Materials Science and Engineering A | Year: 2012

The role of various finishing rolling operations on the texture and mechanical properties has been studied for API (American Petroleum Institute) X100 steel. It has been found that both the finish rolling start and end temperatures influence the final texture and thus, the mechanical properties and the anisotropy of these properties. High temperature finish rolling produces a very weak texture. This texture is a result of dynamic recrystallization, and associated with large grain size and inferior mechanical properties. A slightly delayed start of accelerated cooling led to the formation of large fraction of polygonal ferrite and increased the ductility at the expense of strength. Near-isothermal rolling in the range of 790-810 °C produced the highest texture intensities of both the desired {3. 3. 2}〈1. 1. 3〉 and the undesired {1. 1. 3}〈1. 1. 0〉 components. The latter texture components as well as the {1. 0. 0}〈1. 1. 0〉 component, mitigated the positive effect of the {3. 3. 2}〈1. 1. 3〉 component. On the other hand, a relatively higher finish rolling start temperature (840 °C) and a low finish rolling end temperature (700 °C) suppressed the strength of the {1. 1. 3}〈1. 1. 0〉 and {1. 0. 0}〈1. 1. 0〉 components, while the {3. 3. 2}〈1. 1. 3〉 component apparently was sufficient for the reduction of the anisotropy of mechanical properties. Partial deformation of the quasi-polygonal ferrites also appeared to have contributed to increasing the strength of the investigated steel. © 2011.

EVRAZ Inc. NA | Date: 2015-01-27

Metal rails; metal tracks for rail vehicles; steel rails.

EVRAZ Inc. NA | Date: 2014-06-30

Reinforcing materials of metal for buildings, namely, steel plates and sheets; metal building materials, namely, cladding, bars, beams, rods and tubing; frames of metal for buildings; palings of metal; sheets and plates of metal; steel pipes; steel sheets; steel strips; steel tubes; steel, unwrought or semi-wrought for further manufacture; tubing of metal. Armor for protecting buildings and other structures, aircraft, marine vessels and vehicles against ballistic projectiles; Protective armor panels for protecting against ballistic projectiles and explosive fragments installed in or attached to vehicles, buildings or other structures.

Evraz Inc. Na | Date: 2013-07-18

common metals and their alloys, namely, alloys of common metal; metal building materials, namely, reinforcing materials and structural materials in the nature of metal beams; common metals and their alloys for building purposes, namely, alloys of common metal; materials of metal for railway tracks, namely, railway points, metal railway crossovers and materials for railway construction; non-electric cables and wires of common metal, namely, cable wire; ironmongery in the nature of small items of metal hardware, namely, door handles, hinges, knobs, bolts; metal fasteners, namely, nails, rivets, screws, hooks and latches; letter plates, namely, metal name plates, metal exit devices, namely, metal door bolts, latches, locks, door fittings, door jambs, door stops, door panels, and metal door frames, doorway barriers and cabinet door catches; pipes and tubes of metal; metal safes; goods of common metal not included in other classes, namely, slabs of metal including those from alloy steel and titanium, billets, rails, plates, namely, mail plates, door kick plates and name plates; coil plates, namely, steel in the form of rolled plates; cable wire and rods, namely, metal welding and brazing rods, bars, namely, metal bars for further manufacture, metal pipe couplings and joints, connectors, namely, metal pipe connectors, and metal casings; ores, namely, iron ore and vanadium ore.

Loading EVRAZ INC. NA collaborators
Loading EVRAZ INC. NA collaborators