scholarly journals Press hardening of alternative materials: conventional high- strength steels

2017 ◽  
Vol 11 (5) ◽  
pp. 663-670 ◽  
Author(s):  
Joseba Mendiguren ◽  
Nuria Herrero-Dorca ◽  
Eneko Saenz de Argandoña ◽  
Lander Galdos
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Press Hardening ◽  
Alternative Materials

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>

scholarly journals Combination of press-hardening and isothermal holding in the treatment of high-strength steels

2020 ◽  
Vol 723 ◽  
pp. 012012
Author(s):  
Hana Jirková ◽  
Kateřina Opatová ◽  
Štěpán Jeníček ◽  
Ludmila Kučerová
Keyword(s):  
Isothermal Holding ◽  
High Strength Steels ◽  
High Strength ◽  
Press Hardening

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.

scholarly journals Current Challenges and Opportunities in Microstructure-Related Properties of Advanced High-Strength Steels

2020 ◽  
Vol 51 (11) ◽  
pp. 5517-5586 ◽  
Author(s):  
Dierk Raabe ◽  
Binhan Sun ◽  
Alisson Kwiatkowski Da Silva ◽  
Baptiste Gault ◽  
Hung-Wei Yen ◽  
...  
Keyword(s):  
Recent Progress ◽  
High Strength Steels ◽  
High Strength ◽  
Advanced Characterization ◽  
Critical Discussion ◽  
Press Hardening ◽  
Advanced High Strength Steels ◽  
Bainitic Steels ◽  
Challenges And Opportunities ◽  
Recent Developments

Abstract This is a viewpoint paper on recent progress in the understanding of the microstructure–property relations of advanced high-strength steels (AHSS). These alloys constitute a class of high-strength, formable steels that are designed mainly as sheet products for the transportation sector. AHSS have often very complex and hierarchical microstructures consisting of ferrite, austenite, bainite, or martensite matrix or of duplex or even multiphase mixtures of these constituents, sometimes enriched with precipitates. This complexity makes it challenging to establish reliable and mechanism-based microstructure–property relationships. A number of excellent studies already exist about the different types of AHSS (such as dual-phase steels, complex phase steels, transformation-induced plasticity steels, twinning-induced plasticity steels, bainitic steels, quenching and partitioning steels, press hardening steels, etc.) and several overviews appeared in which their engineering features related to mechanical properties and forming were discussed. This article reviews recent progress in the understanding of microstructures and alloy design in this field, placing particular attention on the deformation and strain hardening mechanisms of Mn-containing steels that utilize complex dislocation substructures, nanoscale precipitation patterns, deformation-driven transformation, and twinning effects. Recent developments on microalloyed nanoprecipitation hardened and press hardening steels are also reviewed. Besides providing a critical discussion of their microstructures and properties, vital features such as their resistance to hydrogen embrittlement and damage formation are also evaluated. We also present latest progress in advanced characterization and modeling techniques applied to AHSS. Finally, emerging topics such as machine learning, through-process simulation, and additive manufacturing of AHSS are discussed. The aim of this viewpoint is to identify similarities in the deformation and damage mechanisms among these various types of advanced steels and to use these observations for their further development and maturation.

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

Flow Curves Prediction of Heat Treated Boron Alloy Steels for Hot Stamping Process

2015 ◽  
Vol 658 ◽  
pp. 81-85
Author(s):  
Prapatsorn Srithananan ◽  
Pongpan Kaewtatip ◽  
Vitoon Uthaisangsuk
Keyword(s):  
Alloy Steel ◽  
Hot Stamping ◽  
High Strength Steels ◽  
High Strength ◽  
Optical Microscope ◽  
Stress Strain ◽  
Flow Curves ◽  
Press Hardening ◽  
Heat Treated ◽  
Alloy Steels

Automotive parts made of ultra-high strength steels (UHSS) have been increasingly produced by hot stamping or press hardening of boron alloy steel. In case of novel hot formed components with tailored properties, different heating cycles needed to be applied for different zones, in which varying microstructure characteristics were generated. Mechanical properties of these parts were thus precisely controlled by the microstructure constituents. In this work, stress-strain behaviors of a boron alloy steel undergoing different heat treatment conditions with respect to that modified hot stamping procedure were predicted. Firstly, boron alloy steel sheet specimens were heated up to the austenitization temperature. Afterwards, they were abruptly cooled down to the bainitic temperature range, held for different holding times and finally cooled to room temperature. The microstructures obtained from each condition were characterized by optical microscope (OM) using color tint etching. The stress-strain responses of all generated microstructures were determined by tensile test. By the modeling, flow curves of the individual single phases were described taking into account a dislocation theory based model and their chemical composition. Subsequently, effective flow curves of the heat treated boron alloy steels were calculated by means of the isostrain and non-isostrain method and were finally compared with the experimentally determined curves.

scholarly journals Integration of Press-Hardening Technology into Processing of Advanced High Strength Steels

2018 ◽  
Vol 941 ◽  
pp. 317-322 ◽  
Author(s):  
Hana Jirková ◽  
Kateřina Opatová ◽  
Josef Káňa ◽  
Dagmar Bublíková ◽  
Martin Bystrianský
Keyword(s):  
Isothermal Holding ◽  
High Strength Steels ◽  
Dimensional Accuracy ◽  
High Strength ◽  
Total Elongation ◽  
Press Hardening ◽  
Advanced High Strength Steels ◽  
Passenger Safety ◽  
Ultra High Strength Steels ◽  
New Processing

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 CO2 emissions. Another important factor is the passenger safety which will improve by the use of these materials. 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 treatments is the isothermal holding time. These holding times are technologically demanding which is why industry seeks new possibilities to integrate new processing methods directly into the production process. One option for making high-strength sheet metals is press-hardening which delivers high dimensional accuracy and a small spring-back effect. In order to test the use of AHSS steels for this technology, a material-technological modelling was chosen. Material-technological models based on data obtained directly from a real press-hardening process were examined on two experimental steels, CMnSi TRIP and 42SiCr. Variants with isothermal holding and continuous cooling profiles were tested. It was found that by integrating the Q&P process (quenching and partitioning) into press hardening, the 42SiCr steel can develop strengths of over 1800 MPa with a total elongation of about 10%. The CMnSi TRIP steel with lower carbon content and without chromium achieved a tensile strength of 1160 MPa with a total elongation of 10%.

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.

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