scholarly journals Making ultrastrong steel tough by grain-boundary delamination

Science ◽  
2020 ◽  
Vol 368 (6497) ◽  
pp. 1347-1352 ◽  
Author(s):  
L. Liu ◽  
Qin Yu ◽  
Z. Wang ◽  
Jon Ell ◽  
M. X. Huang ◽  
...  

Developing ultrahigh-strength steels that are ductile, fracture resistant, and cost effective would be attractive for a variety of structural applications. We show that improved fracture resistance in a steel with an ultrahigh yield strength of nearly 2 gigapascals can be achieved by activating delamination toughening coupled with transformation-induced plasticity. Delamination toughening associated with intensive but controlled cracking at manganese-enriched prior-austenite grain boundaries normal to the primary fracture surface dramatically improves the overall fracture resistance. As a result, fracture under plane-strain conditions is automatically transformed into a series of fracture processes in “parallel” plane-stress conditions through the thickness. The present “high-strength induced multidelamination” strategy offers a different pathway to develop engineering materials with ultrahigh strength and superior toughness at economical materials cost.

Alloy Digest ◽  
2018 ◽  
Vol 67 (9) ◽  

Abstract Ferrium M54 was designed to create a cost-effective, ultra high-strength, high-fracture toughness material with a high resistance to stress-corrosion cracking for use in structural applications. This datasheet provides information on composition, hardness, and tensile properties as well asfatigue. Filing Code: SA-822. Producer or source: QuesTek Innovations, LLC.


1995 ◽  
Vol 393 ◽  
Author(s):  
Toni Grobstein

ABSTRACTThe Partnership for a New Generation of Vehicles (PNGV) is a national initiative with three goals: First, to significantly improve national competitiveness in manufacturing; second, to implement commercially viable innovations from ongoing research on conventional vehicles, and third, to develop a vehicle to achieve up to three times the fuel efficiency of today's comparable vehicle (ie, the 1994 Chrysler Concorde, Ford Taurus, and Chevrolet Lumina). Note this vehicle will have the equivalent customer purchase price of today's vehicles adjusted for economics, while meeting the customers' needs for quality, performance, and utility. Eight federal agencies are currently contributing to these goals, as well as the three principal US automobile manufacturers, numerous automotive component suppliers, research laboratories, and universities.Materials research and development is a significant effort within PNGV. The goals in this area include development of lightweight, recyclable materials for structural applications, high strength, long-life, high temperature materials for engine components, improved materials for alternative propulsion and energy storage systems, and cost-effective process technologies and component fabrication methods. Application of advanced materials to automobiles will involve consideration of diverse factors, including weight savings, affordability, recyclability, crashworthiness, repairability, and manufacturability.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 358
Author(s):  
Lawrence Cho ◽  
Yuran Kong ◽  
John G. Speer ◽  
Kip O. Findley

Recent research efforts to develop advanced–/ultrahigh–strength medium-Mn steels have led to the development of a variety of alloying concepts, thermo-mechanical processing routes, and microstructural variants for these steel grades. However, certain grades of advanced–/ultrahigh–strength steels (A/UHSS) are known to be highly susceptible to hydrogen embrittlement, due to their high strength levels. Hydrogen embrittlement characteristics of medium–Mn steels are less understood compared to other classes of A/UHSS, such as high Mn twinning–induced plasticity steel, because of the relatively short history of the development of this steel class and the complex nature of multiphase, fine-grained microstructures that are present in medium–Mn steels. The motivation of this paper is to review the current understanding of the hydrogen embrittlement characteristics of medium or intermediate Mn (4 to 15 wt pct) multiphase steels and to address various alloying and processing strategies that are available to enhance the hydrogen-resistance of these steel grades.


Author(s):  
Ramakrishna Koganti ◽  
Adrian Elliott ◽  
Charles Orsette

The usage of advanced high strength steel (AHSS) in automotive body structures is projected to grow significantly in the next 5–10 years with the introduction of new safety and fuel economy regulations. This is due to their superior mechanical properties and weight savings potential. These new materials pose significant manufacturing challenges, particularly for welding and stamping. Due to the high strength nature of AHSS materials, higher weld forces and longer weld times are often needed to weld these advanced steels. In this paper, the weldability of 1.4 mm electro galvanized (EG) Dual Phase 780 (DP780) welded to a 1.6 mm Electro Galvanized (EG) Transformation Induced Plasticity 780 (TRIP780) is discussed. Also, weld current lobes, mechanical properties (shear and cross tension), metallographic cross-section and micro-hardness profile in a two-metal stack-up are discussed. Weld Lobes and a full factorial Design of Experiment (DOE) was conducted. Weld current and hold time are the chosen factors for the DOE. Based on the DOE data analysis, weld current was the significant factor for tensile load and hold time was the significant factor for the cross tension load. There were no interaction effects observed between weld current and hold time o for tensile and cross tensions loads.


Author(s):  
R-R. Lee

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.


Alloy Digest ◽  
1998 ◽  
Vol 47 (3) ◽  

Abstract Alcoa 2024 alloy has good machinability and machined surface finish capability, and is a high-strength material of adequate workability. It has largely superseded alloy 2017 (see Alloy Digest Al-58, August 1974) for structural applications. The alloy has comparable strength to some mild steels. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as machining and surface treatment. Filing Code: AL-346. Producer or source: ALCOA Wire, Rod & Bar Division.


Alloy Digest ◽  
1986 ◽  
Vol 35 (7) ◽  

Abstract UNS No. A97075 is a wrought precipitation-hardenable aluminum alloy. It has excellent mechanical properties, workability and response to heat treatment and refrigeration. Its typical uses comprise aircraft structural parts and other highly stressed structural applications where very high strength and good resistance to corrosion are required. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on low temperature performance as well as forming, heat treating, and machining. Filing Code: Al-269. Producer or source: Various aluminum companies.


Sign in / Sign up

Export Citation Format

Share Document