Production of DMR 249A Steel at SAIL, Bokaro Steel Plant

2012 ◽  
Vol 710 ◽  
pp. 149-154 ◽  
Author(s):  
Subrata Mallik ◽  
Biswasi Sunita Minz ◽  
Basudev Mishra
Keyword(s):  
Hydrogen Content ◽  
High Performance ◽  
Raw Materials ◽  
Vacuum Treatment ◽  
Steel Plant ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Structural Applications

Low alloy steels are an attractive option for high performance structural applications due to cost and availability factors. A low carbon low alloyed steel, DMR 249A, was developed for strategic applications by Indian Navy at Steel Melting Shop II, Bokaro Steel Plant (SMS II, BSL). This paper enumerates the detail process variables modified for this development. DMR 249A grade was having the specified gas contents of hydrogen <2 ppm in final product for the avoidance of detrimental phenomenon like “Hair Line Cracks”. So the Hydrogen content of liquid steel was to be less than 3 ppm and this demand vacuum treatment of the steel. In absence of any Degassing unit at SMS II, BSL, making of DMR 249A steel was a challenging task. The hydrogen content of steel was controlled through restriction of hydrogen in input raw materials, control in degree of deoxidation during tapping, slag basicity at ladle furnace, argon rinsing regime and cooling of slabs i.e. control over diffusion of H2. The steel was produced with the existing infrastructure at Bokaro Steel Plant with various alloying elements and processed suitably to obtain the desired yield strength, toughness and gaseous content. The control was exercised at various stages of steel making and hot strip rolling to enable achievement of a higher degree of consistency in mechanical properties and microstructure. Quality fulfillment was a great challenge without vacuum degasser unit but Bokaro successfully made the steel with 100% customer satisfaction.

scholarly journals Computer modeling of microstructural change and strength of low carbon steel in hot strip rolling.

1987 ◽  
Vol 27 (6) ◽  
pp. 439-445 ◽  
Author(s):  
Masayoshi SUEHIRO ◽  
Kazuaki SATO ◽  
Yasushi TSUKANO ◽  
Hiroshi YADA ◽  
Takehide SENUMA ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Computer Modeling ◽  
Low Carbon Steel ◽  
Microstructural Change ◽  
Low Carbon ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Hot Strip

scholarly journals Experimental Study on Adhesion of Oxide Scale on Hot-Rolled Steel Strip

2012 ◽  
Vol 472-475 ◽  
pp. 622-625 ◽  
Author(s):  
Xiang Long Yu ◽  
Dong Bin Wei ◽  
Xiao Dong Wang ◽  
Zheng Yi Jiang
Keyword(s):  
Oxide Scale ◽  
Steel Strip ◽  
Low Carbon Steel ◽  
Physicochemical Characteristics ◽  
Oxide Scales ◽  
Low Carbon ◽  
Laminar Cooling ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Gleeble 3500

An experimental method was developed to study the adherence properties of the oxide scale formed on microalloyed low carbon steel after hot strip rolling. The evolution of the oxide scale during laminar cooling was investigated using Gleeble 3500 Thermal-Mechanical Simulator connected with a humid air generator. After the sample cooled down to ambient temperature, the oxide scale was protected by lacquer to prevent the scale from losing. Physicochemical characteristics of the oxide scale were examined and the adherence mechanism was discussed. Decomposed wustite a mixture of α-iron and magnetite (Fe3O4), can substantially improve the integrity of oxide scale. However, large quantities of hematite (Fe2O3) or retained wustite (FeO) were found detrimental to the adhesion of the oxide scale. It is found that the adherence of oxide scales significantly depends on the phase composition of oxide scales with different thickness.

Ceramics

MRS Bulletin ◽  
1987 ◽  
Vol 12 (7) ◽  
pp. 25-28
Author(s):  
Robert J. Eagan
Keyword(s):  
High Performance ◽  
Space Shuttle ◽  
Raw Materials ◽  
Low Cost ◽  
Flat Glass ◽  
Grain Morphology ◽  
Heat Engines ◽  
Structural Applications ◽  
Simple Processing ◽  
Traditional Ceramics

Until the 1980s, most people thought of ceramics as artware and artifacts. The recent development of advanced ceramics for high performance thermal insulation (space shuttle tiles), high temperature structures (heat engines), and electronics (superconductors) has dramatically changed perceptions about the utility of ceramics.High technology ceramics are related to “traditional” ceramics only to the extent that they are inorganic, nonmetallic materials. Traditional ceramics are derived from minerals. For example, dinnerware and bricks consist mostly of clay, while sand is the major ingredient in flat glass and containers. Abundant raw materials, simple processing, adequate performance at low cost, and technological evolution have kept these industries viable for several thousand years.But, for demanding electronic or structural applications, synthesizing ceramics from minerals is often unacceptable. The chemical variability of mineral deposits, the difficulty of obtaining a homogeneous mixture of powders, and the problems of consolidating the powders into a uniform ceramic with desirable grain morphology, chemistry and grain boundary phases have stimulated the development of chemically derived ceramic precursors.

scholarly journals Cost Analysis of Various Factors for Geopolymer 3D Printing of Construction Products in Factories and on Construction Sites

Recycling ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 60
Author(s):  
Qaisar Munir ◽  
Timo Kärki
Keyword(s):  
3D Printing ◽  
Carbon Dioxide Emissions ◽  
High Performance ◽  
Raw Materials ◽  
Research Work ◽  
Transportation Cost ◽  
Raw Material ◽  
Low Carbon ◽  
Construction Sites ◽  
Construction Products

The utilization of geopolymer 3D printing for construction products in recent years has been exceptionally substantial, owing to their low carbon dioxide emissions, high-performance properties such as durability, and good thermal and mechanical properties. This automated manufacturing process reduces the need for additional formworks, capital investments, and human resources. Geopolymer 3D printing development is emerging because of its advanced use in construction applications. However, high costs of the initial stages of geopolymer production and 3D printing has inhibited the development of this technology in many countries. This research presents a comprehensive economic evaluation of the investment for each principal stage that facilitates a better deployment of the resources. The study investigated all phases of geopolymer production, from the extraction of raw materials to printing. The cost for the four fundamental stages, namely raw material availability and transportation, pretreatments for raw materials, parameter selection and strength requirements, and printing in factories and on construction sites, were analyzed. The results show that 3D printing of a geopolymer on a construction site is economically more advantageous compared to printing in the factory. The study also verified that raw material transportation cost has the least effect on the finished product cost, whereas pretreatments of raw material and mixing parameters significantly influenced the ultimate cost of the product. Finally, research work suggested the need for future tasks to make geopolymer 3D printing a viable construction approach.

Effect of Nb Content on Hot Flow Stress, Dynamic Recrystallization and Strain Accumulation Behaviors in Low Carbon Bainitic Steel

2010 ◽  
Vol 654-656 ◽  
pp. 62-65 ◽  
Author(s):  
Cheng Liang Miao ◽  
Guo Dong Zhang ◽  
Cheng Jia Shang
Keyword(s):  
Dynamic Recrystallization ◽  
Rolling Process ◽  
Carbon Steels ◽  
Compressive Deformation ◽  
Strain Accumulation ◽  
Low Carbon ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Compression Process ◽  
Single Pass

Compressive deformation behaviors of low carbon steels with different Nb contents were investigated in the temperature range 900oC to 1100oC and strain rates from 0.05s-1 to 2s-1 by single pass deformation. Multi-pass compressive deformation processes were also carried out to examine strain accumulation under different Nb contents. In single pass deformations, dynamic recrystallization (DRX) can be observed in the case of low strain rate and high temperature, and the higher Nb steel exhibits higher deformation activation energy (Qdef) and critical strain value (εc) for the onset of DRX. However during multi-pass compression process (interval time of 3-4s), the higher Nb steel has larger strain accumulation between passes, so it is easier for high Nb steel that DRX happens during hot strip rolling process, which starts at relative high rolling temperature.

scholarly journals Simulation of the Refining Process of Ultra-Low Carbon (ULC) Steel

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 893
Author(s):  
Dali You ◽  
Christian Bernhard ◽  
Andreas Viertauer ◽  
Bernd Linzer
Keyword(s):  
Current Trend ◽  
Submerged Entry Nozzle ◽  
Refining Process ◽  
Interstitial Free ◽  
Low Carbon ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Thin Slab Casting ◽  
Production Route ◽  
Slab Casting

The standard production route for mild steels for automotive purposes is still based on conventional continuous casting (CC) and hot strip rolling (HSR). The current trend towards the "zero-carbon car" will demand the abating of material emissions in the future. Thin slab casting and direct rolling (e.g., Arvedi endless strip production (ESP)) is an approach to reduce CO2 emissions by 50% compared to CC and HSR. One of the main limitations in applying ESP for the production of ultra-low carbon/interstitial free (ULC/IF) steels is clogging. Clogging is the blockage of the submerged entry nozzle due to the build-up of oxide layers or an oxide network. The high clogging sensitivity of IF steels results most probably from the FeTi addition, and hence, a general change of the deoxidation practice might be an option to overcome these problems. In the present work, the thorough refining process of ULC steel was simulated by addressing the different deoxidation routes and the influence of titanium (Ti) alloying on steel cleanness. The developed ladle furnace (LF) and the Ruhrstahl Heraeus (RH) refining models were applied to perform the simulation. Before the simulations, the models are briefly described and validated by the published industrial data.

scholarly journals Effect of Coiling Temperature on Oxide Scale of Hot-Rolled Strip

2011 ◽  
Vol 415-417 ◽  
pp. 853-858 ◽  
Author(s):  
Xiang Long Yu ◽  
Zheng Yi Jiang ◽  
Xiao Dong Wang ◽  
Dong Bin Wei ◽  
Quan Yang
Keyword(s):  
Phase Composition ◽  
Oxide Scale ◽  
Low Carbon Steel ◽  
Rolled Strip ◽  
Low Carbon ◽  
Hot Strip Rolling ◽  
Coiling Temperature ◽  
Strip Rolling ◽  
Hot Rolled Strip ◽  
Hot Rolled

The influence of the coiling temperature, ranging from 550 to 570°C, on the morphology and the phase composition of the oxide scale formed on the microalloyed low carbon steel for automobiles after hot strip rolling was investigated. Physicochemical characteristics of the oxide scales were examined and their formation mechanism was discussed. Thickness of the oxide scale is in the range of 8-11µm and decreases with a decrease of coiling temperature. The microstructure and phase composition, XRD analysis shows a large amount of magnetite (Fe3O4) and some sparse hematite (Fe2O3) exist on the surface of hot rolled strip when the coiling temperature reduces from 570 to 550°C. The coiling temperature substantially affects the internal microstructure and magnetite phase.

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