Phillips A.,Monash University |
Kaul H.,Bluescope Steel Ltd. |
Burg J.,Bluescope Steel Ltd. |
Killmore C.,Bluescope Steel Ltd. |
And 3 more authors.
ISIJ International | Year: 2011
Twin roll casting (TRC) of low-carbon ultra-thin cast strip (UCS) steel has the potential to deliver significant economic advantages over steels made by conventional processes. Novel microstructures containing intragranularly nucleated acicular ferrite may be produced in UCS products manufactured by the CASTRIP®* process, however, their mechanical property performance has yet to be fully evaluated. This study compared the mechanical properties and edge formability of UCS steel produced by the CASTRIP process to steel produced by conventional hot rolled (HR) and cold rolled and continuously annealed (CR & CA) process routes. The results revealed an apparent paradox, where recent UCS steel produced by the CASTRIP process was shown to have lower total tensile elongation values, yet higher edge formability than products manufactured by the conventional process routes. The discrepancy was largely attributable to the influence of acicular ferrite microstructure on steel plasticity. Acicular ferrite decreased macroplasticity by reducing the contribution of yield point elongation (lower volume fraction of pro-eutectoid ferrite) and post uniform elongation (strain localisation to softer pro-eutectoid ferrite) components of the total tensile elongation value. Conversely, the high homogeneity of the acicular ferrite microstructure enhanced micro-plasticity of the UCS steel produced by improving resistance to void initiation and propagation during forming. This study also showed that plastic anisotropy can significantly influence the edge formability of low-carbon sheet steel, with failure occurring along the direction where the resistance to through thickness thinning was the least. © 2011 ISIJ.
Edelman D.G.,Nucor Steel Indiana |
Campbell P.C.,Nucor Steel Indiana |
Killmore C.R.,Bluescope Steel Ltd. |
Carpenter K.R.,Bluescope Steel Ltd. |
And 3 more authors.
AISTech - Iron and Steel Technology Conference Proceedings | Year: 2011
A range of Ultra-Thin Cast Strip (UCS) sheet steels with elevated residual levels was produced via the CASTRIP® twin drum casting method at Nucor Steel, Indiana. This paper examines the influence of elevated levels of copper, chromium, nickel, and phosphorous on mechanical properties, surface quality, processing, and weldability of UCS sheet steel products produced by the CASTRIP process. Increased levels of copper and phosphorous were found to strengthen UCS sheet steel due to solid solution strengthening but chromium and nickel did not. At lower coiling temperatures and low hot reductions, where processing conditions promote microstructural strengthening, copper and chromium further enhanced strength via increased hardenability. The presence of elevated residual levels of copper is known to potentially lead to hot shortness, unless expensive counter measures are employed, such as nickel additions. Due to the unique solidification and thermal history conditions of the CASTRIP process, higher levels of copper can be tolerated without hot shortness or loss of surface quality. The CASTRIP process is capable of utilizing increased levels of scrap containing higher residual levels, such as post-consumer shredded material. These elevated levels of residual elements can be utilized as a strengthening agent in the finished sheet. Alternatively, this influence on strength can be mitigated when desired through the choice of processing parameters. Additionally, the elevated residual content did not influence either the surface quality or the weldability of the steel.
Bevans K.,ThyssenKrupp |
Chott M.,Megamet Solid Metals Inc. |
Ensor B.,Meltshop metallurgist |
Fitzgerald J.,Timken Co. |
And 6 more authors.
Iron and Steel Technology | Year: 2013
A review of the importance of advanced high-strength steels (AHSS) and electronic units on the recycling of automobiles is presented. AHSS which offer yield strengths of more than 300 MPa and tensile strengths exceeding 600 MPa are gaining significance in the vehicle manufacturing sector. The category of AHSS covers steel types, such as dual-phase (DP), transformation induced plasticity (TRIP), complex-phase (CP) and martensitic steels (MART), which derive their enhanced properties from alloying additions. Demand for the recycling of AHSS will continue to increase in the future with the necessity to design a process that is feasible and effective is essential to the future use of this material. AHSS are characterized by their high strength, which have allowed automakers to reduce the gauge for structural members in the automotive body-in-white.
Becker M.,Nucor Steel Indiana
Pipe and Tube Pittsburgh 2010 | Year: 2010
The CASTRIP facility at Nucor's Crawfordsville, Indiana plant utilizes a twin-roll casting process to produce light gauge hot rolled and hot rolled galvanized products for use in a variety of industries, including ERW tubing applications. The thickness range and mechanical properties available permit applications that were previously produced using cold rolled steel to be manufactured using CASTRIP hot rolled material. © (2010) by the International Tube Association. All rights reserved.
Geldenhuis J.M.A.,Nucor Steel Indiana |
Murray D.G.,Nucor Steel Indiana |
Burke D.E.,Nucor Steel Indiana |
Swank D.L.,Nucor Steel Indiana |
And 7 more authors.
Iron and Steel Technology | Year: 2010
The increase in barrel refractory brick erosion that occurred at the Nucor Crawfordsville meltshop was mitigated by implementing a combination of operational practices and ladle preheating practices.
Birkbeck C.,Nucor Steel Indiana |
Schwabe C.,Nucor Steel Indiana |
Ryan S.,Nucor Steel Indiana
Iron and Steel Technology | Year: 2010
The Nucor Steel-Indiana CSP mill is aimed towards upgrading and modifying its two arc furnaces and meltshop mill with the use of reliable and high performance electric arc furnace (EAF) on-load tap changers. Part of the project comprised a significant decrease in the number of unplanned maintenance events, allowing increased availability and utilization of the arc furnaces. In this direction, diverter tips were no longer replaced on location, proving to be a quicker and more reliable method of maintaining the diverter assemblies. Nucor also purchased a Kelman TAPTRANS gas-in-oil monitor and commissioned it on one of the arc furnace transformers as a beta test site installation. The process by which the TAPTRANS equipment analyzes the automatically drawn oil sample is unique in the gas-in-oil analysis industry, using a process known as photo-acoustic spectroscopy.