Thermo-Mechanical Hardening of Ultra High-Strength Steels

2013 ◽  
Vol 549 ◽  
pp. 133-140
Author(s):  
Werner Homberg ◽  
Tim Rostek
Keyword(s):  
Mechanical Properties ◽  
State Of The Art ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Treatments ◽  
Press Hardening ◽  
Martensitic Microstructure ◽  
Ultra High Strength Steels

nnovative ultra high-strength steels have excellent mechanical properties which commonly relate to the materials martensitic microstructure. As thermal heat treatments are state-of-the-art for obtaining the desired microstructure, innovative thermo-mechanical treatments are likely to give rise to even better material qualities. This article highlights various aspects of innovative thermo-mechanical hardening strategies for the processing of ultra high-strength steels, involving both press hardening and friction spinning operations.

scholarly journals USE OF MULTI-PHASE TRIP STEEL FOR PRESS-HARDENING TECHNOLOGY

2019 ◽  
Vol 25 (2) ◽  
pp. 101 ◽  
Author(s):  
Hana Jirková ◽  
Kateřina Opatová ◽  
Štěpán Jeníček ◽  
Jiří Vrtáček ◽  
Ludmila Kučerová ◽  
...  
Keyword(s):  
Trip Steel ◽  
Physical Simulation ◽  
Isothermal Holding ◽  
High Strength Steels ◽  
High Strength ◽  
Press Hardening ◽  
Passenger Safety ◽  
Ultra High Strength Steels ◽  
New Treatments ◽  
Multi Phase

<p class="AMSmaintext">Development of high strength or even ultra-high strength steels is mainly driven by the automotive industry which strives to reduce the weight of individual parts, fuel consumption, and CO<sub>2</sub> emissions. Another important factor is to improve passenger safety. In order to achieve the required mechanical properties, it is necessary to use suitable heat treatment in addition to an appropriate alloying strategy. The main problem of these types of treatments is the isothermal holding step. For TRIP steels, the holding temperature lies in the field of bainitic transformation. These isothermal holds are economically demanding to perform in industrial conditions. Therefore new treatments without isothermal holds, which are possible to integrate directly into the production process, are searched. One way to produce high-strength sheet is the press-hardening technology. Physical simulation based on data from a real-world press-hardening process was tested on CMnSi TRIP steel. Mixed martensitic-bainitic structures with ferrite and retained austenite (RA) were obtained, having tensile strengths in excess of 1000 MPa.</p>

Mechanical properties and microstructural evaluation of the heat-affected zone in ultra-high strength steels

2020 ◽  
Vol 157 ◽  
pp. 107072
Author(s):  
Mohsen Amraei ◽  
Shahriar Afkhami ◽  
Vahid Javaheri ◽  
Jari Larkiola ◽  
Tuomas Skriko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
High Strength Steels ◽  
High Strength ◽  
Microstructural Evaluation ◽  
Ultra High Strength Steels

Tools and Technologies for Hot Forming with Local Adjustment of Part Properties

2010 ◽  
Vol 638-642 ◽  
pp. 3919-3924 ◽  
Author(s):  
Ralf Kolleck ◽  
Robert Veit
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Strength Distribution ◽  
Body Parts ◽  
Press Hardening ◽  
Uniform Strength ◽  
University Of Technology ◽  
Ultra High Strength Steels ◽  
Conventional Press ◽  
The Moment

In general hot stamped car body parts show a uniform strength distribution. Especially for safety relevant parts with high requirements concerning crash performance, this uniform strength distribution can cause problems. During a crash a B-pillar e. g. can absorb more energy when the lower part is relatively flexible while the middle and upper part has to be high-tensile to prevent the intrusion into the passenger compartment. Also during the production of hot stamped parts, the high strength causes trouble. When the trimming takes place after the hardening process, the durability of the tool is limited. Thus at the moment the only economic process for trimming of ultra-high-strength steels is laser cutting. This paper presents different approaches to reach local different strength distributions in hot stamped components. In particular the results of a research project of the Institute Tools & Forming, Graz University of Technology are shown where precisely defined areas of different strengths could be obtained in one part. This was achieved by the use of simple and cheap ceramic inserts in conventional press hardening tools.

Press hardening of alternative high strength aluminium and ultra-high strength steels

2016 ◽  
Author(s):  
Joseba Mendiguren ◽  
Rafael Ortubay ◽  
Xabier Agirretxe ◽  
Lander Galdos ◽  
Eneko Sáenz de Argandoña
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Press Hardening ◽  
Ultra High Strength Steels

Mechanical properties and microstructure of low carbon ultra-high strength steels (UHSS) microalloyed with boron

2012 ◽  
Vol 1373 ◽  
Author(s):  
I. Mejía ◽  
A. García de la Rosa ◽  
A. Bedolla-Jacuinde ◽  
J.M. Cabrera
Keyword(s):  
Mechanical Properties ◽  
Research Work ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Tests ◽  
Low Carbon ◽  
Advanced High Strength Steels ◽  
New Family ◽  
Ultra High Strength Steels ◽  
Hot Rolled

ABSTRACTThe aim of this research work is to study the effect of boron addition on mechanical properties and microstructure of a new family of low carbon NiCrVCu advanced high strength steels (AHSS). Experimental steels are thermo-mechanically processed (TMP) (hot-rolled+quenched). Results show that the microstructure of these steels contains bainite and martensite, predominantly, which nucleate along prior austenite grain boundaries (GB). On the other hand, tensile tests reveal that the TMP steels have YS (0.2% offset) of 978 MPa, UTS of 1140 MPa and EL of 18%. On the basis of exhibited microstructure and mechanical properties, these experimental steels are classified as bainitic-martensitic complex phase (CP) advanced ultra-high strength steels (UHSS).

scholarly journals Understanding Mechanical Properties of Nano-Grained Bainitic Steels from Multiscale Structural Analysis

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 426 ◽  
Author(s):  
Caballero ◽  
Rementeria ◽  
Morales-Rivas ◽  
Benito-Alfonso ◽  
Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Extreme Conditions ◽  
Transformation Theory ◽  
Enabling Technology ◽  
Bainitic Steels ◽  
Steel Sector ◽  
Hardening Mechanisms ◽  
Ultra High Strength Steels

Steel components working in extreme conditions require materials presenting the highest performances. Nowadays, nanoengineering is being applied to the development of ultra-high strength steels as a key-enabling technology in the steel sector. The present article describes the multiscale structure of nano-grained steels designed using atomic transformation theory and processed by a simple heat treatment. Outstanding mechanical properties for these novel steels are reported, and strain-hardening mechanisms are discussed.

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