Crash Behaviour of Various Modern Steels Exposed to High Deformation Rates

2007 ◽  
Vol 344 ◽  
pp. 151-158 ◽  
Author(s):  
Till Laumann ◽  
Markus Pfestorf ◽  
Andreas Beil ◽  
Manfred Geiger ◽  
Marion Merklein
Keyword(s):  
Test Bench ◽  
Microscopic Analysis ◽  
High Strength ◽  
The Body ◽  
Absorbed Energy ◽  
Maximum Deformation ◽  
High Deformation ◽  
Complex Shapes ◽  
Body In White ◽  
Crash Behaviour

The increasing call for significant safety improvements of new cars requires, among other important relevant aspects, the application of high strength materials for the body in white. Quenchable manganese boron alloyed steels like 22MnB5 offer superior strength values, complex shapes and enhanced accuracy. For the evaluation of the crash appropriateness specimens in different annealed states are deformed in a so called drop test bench and hereupon judged in terms of absorbed energy, maximum deformation and other aspects like wrinkling behaviour. Microscopic analysis complements the evaluation of crash-appropriateness.

Relationship between Microstructure and Mechanical Properties in Q&P-Steels

2016 ◽  
Vol 879 ◽  
pp. 1933-1938 ◽  
Author(s):  
Richard G. Thiessen ◽  
Georg Paul ◽  
Roland Sebald
Keyword(s):  
Mechanical Properties ◽  
Dual Phase Steel ◽  
High Strength Steels ◽  
High Strength ◽  
The Body ◽  
Advanced High Strength Steels ◽  
Passenger Safety ◽  
Back Scattering ◽  
Body In White ◽  
Expected Increase

Third-Generation advanced high strength steels are being developed with the goal of reducing the body-in-white weight while simultaneously increasing passenger safety. This requires not only the expected increase in strength and elongation, but also improved local formability. Optimizing elongation and formability were often contradictory goals in dual-phase steel developments. Recent results have shown that so-called "quench and partitioning" (Q&P) concepts can satisfy both requirements [1]. Many Q&P-concepts have been studied at thyssenkrupp Steel Europe. Thorough investigation of the microstructure has revealed relationships between features such as the amount, morphology and chemical stability of the retained austenite and the obtained mechanical properties. An evaluation of the lattice strain by means of electron-back-scattering-diffraction has also yielded a correlation to the obtained formability. The aim of this work is to present the interconnection between these microstructural features and propose hypotheses for the explanation of how these features influence the macroscopically observed properties.

scholarly journals Corner Strengthening by Local Thickening and Ausforming Using Planar Compression in Hot Stamping of Ultra-High Strength Steel Parts

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1977
Author(s):  
Tomoyoshi Maeno ◽  
Ken-ichiro Mori ◽  
Hiroki Homma ◽  
Ali Talebi-Anaraki ◽  
Ryohei Ikeda
Keyword(s):  
Plastic Deformation ◽  
Hot Stamping ◽  
High Strength ◽  
The Body ◽  
Bending Rigidity ◽  
Large Plastic Deformation ◽  
Shape Accuracy ◽  
Ultra High Strength Steel ◽  
Shaped Part ◽  
Body In White

Hot-stamped products are widely used for the body-in-white of an automobile as they are lightweight and improve crashworthiness. A hot-stamping process using planar compression was developed to strengthen corners of ultra-high strength parts by local thickening and hardening. In this process, the corners are thickened by compressing the blank in the planar direction with the upper and lower dies while blocking the movement of both edges with stoppers in the latter stage of forming. Thickening of the corners largely heightens the strength of the formed parts. Not only the thickness but also the hardness of the corner was increased by large plastic deformation and die quenching. For a hot hat-shaped part, a 30% increase in thickness and a 530 HV20 hardness around the corners were attained. The bending rigidity and strength of the formed parts thickened by 30% in the corners increased by 25% and 20%, respectively. In addition, the improvements of the part shape accuracy and the sidewall quenchability were obtained.

Manufacturing of High Strength Steel and Aluminum for a Mixed Material Body in White

2005 ◽  
Vol 6-8 ◽  
pp. 109-126 ◽  
Author(s):  
Markus Pfestorf
Keyword(s):  
Manufacturing Process ◽  
High Strength Steel ◽  
Adhesive Bonding ◽  
Welding Process ◽  
High Strength ◽  
The Body ◽  
Functional Benefit ◽  
Body In White ◽  
Mixed Material ◽  
Forming Tools

Sophisticated materials like high strength steel or even multi phase steel as well as aluminum require more efforts within the manufacturing process than conventional steel sheets as they have been used in the body in white recently. The manufacturing process itself as well as engineering of the parts, material of the forming tools as well as cold and warm joining technologies must be regarded separately. For forming tools coated steel inserts or sometimes even cooling is essential in terms of high-volume car series production. In mixed material solutions using steel in combination with aluminum, the common used resistance spot welding process does not work any more. To maintain high process stability of cold joining technologies combined with adhesive bonding a new process must have been developed. Other items for weight and cost savings are tailored rolled blanks or sophisticated joining technologies. Regarding the manufacturing costs, a cost effective combination of the mentioned high-sophisticated alloys with conventional material should be achieved. Developing a design concept due to crash, stiffness and driving performance, basic requirements have to be considered. This aims to check the high potential of cost intensive materials wherever high functional benefit is necessary under commercial aspects.

Development of Cooled Tools for Press Hardening of Boron Steel Sheets

2007 ◽  
Vol 344 ◽  
pp. 225-232 ◽  
Author(s):  
Ralf Kolleck ◽  
Stefan Pfanner ◽  
E.P Warnke
Keyword(s):  
High Strength ◽  
The Body ◽  
Boron Steel ◽  
Forming Process ◽  
Cycle Times ◽  
Press Hardening ◽  
Steel Sheets ◽  
Fundamental Part ◽  
Body In White ◽  
Crash Tests

Two central topics of modern automotive constructions refer to automotive lightweight constructions and safety; this is best indicated by the most various developments in the context of body constructions. The consistent evaluation of cars by means of crash tests has led to the fact that new manufacturing variants combined with the use of high and ultra high strength materials represent a fundamental part of the body in white. One possibility to form such materials is given by the hot forming process. An innovative approach, namely to improve this procedure in economic and technological terms, is represented by the new tool system for tempered forming processes carried out at the Institute Tools & Forming (T&F). The integration of most complex cooling duct geometries by casting integral tube networks into the tool represents an innovative possibility to improve the cooling performance combined with the reduction of the cycle times.

Modeling and Simulation of Q&P Steels

2016 ◽  
Vol 879 ◽  
pp. 1454-1458
Author(s):  
Georg Paul ◽  
Richard G. Thiessen
Keyword(s):  
Automotive Industry ◽  
High Strength Steels ◽  
High Strength ◽  
The Body ◽  
Special Focus ◽  
High Tensile Strength ◽  
Advanced High Strength Steels ◽  
Passenger Safety ◽  
Steel Grades ◽  
Body In White

Two important objectives of the automotive industry are the decrease of the body-in-white weight and the improvement of the passenger safety. High strength steels (HSS) are widely used to achieve these objectives. Quenching and partitioning (Q&P) has recently been proposed to achieve high strength steel grades for the third generation of advanced high strength steels (AHSS), which contain a considerable amount of retained austenite. Due to their microstructure these new steel grades combine a high tensile strength with good elongation values, as long as cementite precipitation is avoided. A model describing the involved phase transformations is presented. Special focus is put on the cementite precipitation and how it is influenced by silicon and aluminum additions.

BERYLCO NICKEL ALLOY 440

Alloy Digest ◽  
1975 ◽  
Vol 24 (9) ◽  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Nickel Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Electronic Components ◽  
High Temperature Mechanical Properties ◽  
Temperature Performance ◽  
Solution Treated ◽  
Complex Shapes

Abstract BERYLCO NICKEL ALLOY 440 is an age-hardenable nickel-beryllium-titanium alloy that offers high strength, excellent spring properties outstanding formability, good high-temperature mechanical properties, and resistance to corrosion and fatigue. Complex shapes can be produced in the solution-treated (soft) condition and then aged to a minimum tensile strength of 215,500 psi. It is used for mechanical and electrical/electronic components in the temperature range -320 to 800 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-94. Producer or source: Kawecki Berylco Industries Inc.. Originally published September 1964, revised September 1975.

Experimental Analysis of Static Stiffness for Vehicle Body in White

2012 ◽  
Vol 248 ◽  
pp. 69-73 ◽  
Author(s):  
Shu Ming Chen ◽  
Xue Wei Song ◽  
Chuan Liang Shen ◽  
Deng Feng Wang ◽  
Wei Li
Keyword(s):  
Test Bench ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Vehicle Body ◽  
Torsional Angle ◽  
Static Stiffness ◽  
Torsional Deformation ◽  
Automotive Body ◽  
Body In White ◽  
Stiffness Characteristics

In order to know the static stiffness characteristics of the vehicle body in white, the bending stiffness and torsional stiffness of an automotive body in white were tested on a test bench of the static stiffness of an automotive BIW. The bending stiffness and bending deformation of the bottom of the BIW were determined. Also, the torsional stiffness and torsional deformation of the bottom of the BIW were obtained. The fitting curves and equations between loading torque and torsional angle were acquired at clockwise and counterclockwise loading, respectively.

Influence of shape of impactormade from high-strength steel on its fracture at high deformation rates

2021 ◽  
pp. 44-51
Author(s):  
P.A. Radchenko ◽  
◽  
S.P. Batuev ◽  
A.V. Radchenko ◽  
◽  
...  
Keyword(s):  
Finite Element Method ◽  
Fracture Criterion ◽  
Three Dimensional ◽  
High Strength ◽  
Head Part ◽  
The Finite Element Method ◽  
Plastic Deformations ◽  
High Deformation ◽  
Limit Value ◽  
Interaction Velocity

The fracture of high-strength impactor in interaction with a steel barrier is investigated. Three typesof head parts of the impactor are considered: flat, hemispherical and ogival. Normal and oblique interactions with velocities of 700 and 1000 m/s are investigated. Modeling is carried out by the finite element method in a three-dimensional formulation using the author's software EFES 2.0.The limit value of intensity of plastic deformations is used as a fracture criterion. The influence of the striker head part shape, interaction velocity, interaction angle on the fracture of the impactor and the barrier has been investigated. Conditions under which the striker ricochets were defined.

Impact Absorbed Energy of Hat Square Column in High Strength Steels

1996 ◽  
Author(s):  
Akihide Yoshitake ◽  
Kentaro Sato ◽  
Tomoyoshi Okita
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Absorbed Energy

Fabrication of α-TCP, HAp Functionally Graded Porous Beads

2008 ◽  
Vol 57 ◽  
pp. 135-138
Author(s):  
Yuji Kajihata ◽  
Teruo Asaoka ◽  
Katsuko S. Furukawa ◽  
Takashi Ushida ◽  
T. Tateishi
Keyword(s):  
Surface Layer ◽  
High Strength ◽  
Functionally Graded ◽  
The Body ◽  
Acid Solutions ◽  
Bioactive Material ◽  
Hydrolytic Reaction ◽  
Rate Of Absorption ◽  
Porous Beads ◽  
Good Cell

HAp (Hydroxyapatite) and α-TCP (alpha tribasic calcium phosphate) are non-toxic to human cells and, thus, have been studied for applications as biomaterials. HAp is a bioactive material that is not readily absorbed by the body; it offers both high strength and better tissueadhesive properties than α-TCP. In contrast, α-TCP is highly bioabsorbable; it is quickly absorbed by the body, and, therefore, for example, disappears before bone is completely replaced. If porous beads could be fabricated that would take advantage of the useful properties of α-TCP and HAp, they could be used as excellent scaffolds for cultivating cells. In the present study, ceramic beads with α-TCP at the center were fabricated and coated with a functionally graded film of HAp. A scaffold based on this configuration would be expected to have the following characteristics: good cell adhesion; strong beads; and a rate of absorption into the body that would be easy to control. In addition, to accelerate the formation of porous structure, some acid solutions were used to dissolve the beads surface layer and to penetrate pores toward inside of the bead. HAp formation through hydrolytic reaction seemed to be promoted by these acid solutions.

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