Springback evaluation for TRIP 800 steel sheets by simple bending tests

2012 ◽  
Author(s):  
F. J. Avellaneda ◽  
V. Miguel ◽  
J. Coello ◽  
A. Martínez ◽  
A. Calatayud
Keyword(s):  
Bending Tests ◽  
Steel Sheets

Experimental Study of the Formability of H240LA Steel Sheets under Stretch-Bending Conditions

2013 ◽  
Vol 549 ◽  
pp. 349-355 ◽  
Author(s):  
L.H. Martínez-Palmeth ◽  
Andrés Jesús Martínez-Donaire ◽  
C. Vallellano ◽  
G. Centeno ◽  
F.J. García-Lomas
Keyword(s):  
Strain Gradient ◽  
Sheet Thickness ◽  
Time Dependent ◽  
Bending Tests ◽  
Steel Sheets ◽  
Stretch Bending ◽  
R Ratio ◽  
Punch Radius ◽  
Different Diameters ◽  
Hemispherical Punch

The present work discusses the effect of the punch radius on the formability of H240LA steel sheets of 1.2mm thickness. A series of hemispherical punch tests (Nakazima tests) and stretch-bending tests with cylindrical punches of different diameters have been carried out in order to characterize the influence of the strain gradient in the sheet failure. The limit strains have been obtained using a recently proposed time-dependent methodology, which is applicable not only in conventional Marciniak and Nakazima tests, but also in situations with a severe strain gradient through the sheet thickness. The results show that formability of H240LA steel sheets increases as the t0/R ratio decreases.

Ductile Damage in Tension and Bending for DP980 Steel Sheets

2013 ◽  
Vol 554-557 ◽  
pp. 110-117 ◽  
Author(s):  
Julien Troufflard ◽  
Guillermo Requena ◽  
Sandrine Thuillier ◽  
Éric Maire
Keyword(s):  
Volume Fraction ◽  
Sheet Thickness ◽  
Void Volume ◽  
Bending Test ◽  
Isotropic Hardening ◽  
Bending Tests ◽  
Gtn Model ◽  
Volume Fractions ◽  
Steel Sheets ◽  
Dp980 Steel

The mechanical behavior of DP980 steel sheets of 1.7 mm thickness has been investigated with both tensile and bending tests. Free bending tests were performed on square samples of 60mm side. The bending tool has a sharp radius of around 0.4 mm and the sample simply lies on two rollers. Scanning electron micrography observations were performed in order to check the occurrence of cracks, that indicate the onset of rupture in bending. Moreover, X-ray microtomography observations were performed on smooth and notched tensile specimen, with a specific small-size geometry, and bending specimen. Maximum void volume fractions of 1.5 10-3were recorded and the influence of the triaxiality ratio was investigated, by changing the notch radius. In the case of bending, samples were cut in the bent area and void volume fraction distribution was analyzed along the sheet thickness. Material parameters for Gurson-Tvergaard-Needleman (GTN) model, associated with isotropic hardening and von Mises yield criterion, were identified from the tensile tests. Inverse identification was performed over the different sample geometries, showing that GTN model can not capture the triaxiality ratio influence. Finite element simulations of the bending test were then carried out, in order to compare experimental and predicted void volume fractions in the sheet thickness.

A Proposal for Bending Process of TRIP Steel Sheets Based on the Springback Behavior

2012 ◽  
Vol 498 ◽  
pp. 13-18 ◽  
Author(s):  
F.J. Avellaneda ◽  
Valentin Miguel-Eguía ◽  
Juana Coello ◽  
Alberto Martínez ◽  
Antonio Calatayud
Keyword(s):  
Influence Factor ◽  
Elastic Recovery ◽  
Bending Tests ◽  
Trip Steels ◽  
Material Recovery ◽  
Steel Sheets ◽  
Bending Process ◽  
Theoretical Predictions ◽  
Bending Radius ◽  
A Minor

TRIP steels, or Transformed Induced Plasticity steels, have excellent mechanical properties if compared with conventional steels. The highlighted characteristic of these steels is that they modify the microstructure with the deformation process as part of the austenite transforms to martensite, with the consequent change of the material properties. One of the main problems of TRIP steels is strong elastic recovery, or springback, after forming. In this work, the springback phenomenon is evaluated by bending tests and the influence of the variables involved in it is determined. Experimental bending forces do not agree with theoretical predictions that are proposed in the literature. In spite of the bending radius having been considered an influence factor in the process, this work demonstrates that the aforementioned factor has a minor influence, at least for TRIP 800. The factor found to affect material recovery the most was the bending angle.

Structure heterogeneity and mechanical properties studied in thickness up to 100 mm of low-alloyed shipbuilding steel sheets with a yield strength not less than 420 MPa

2021 ◽  
pp. 9-27
Author(s):  
O. V. Sych ◽  
S. V. Korotovskaya ◽  
E. I. Khlusova ◽  
G. D. Motovilina ◽  
V. R. Nikitina
Keyword(s):  
Low Temperatures ◽  
Subgrain Structure ◽  
Structural Elements ◽  
Bending Tests ◽  
Shipbuilding Steel ◽  
Steel Sheets ◽  
Structure Heterogeneity ◽  
Impact Bending ◽  
Average Size ◽  
Lath Morphology

This paper presents a study of changes in the structure and properties in thickness of rolled sheets up to 100 mm of low-alloyed shipbuilding steel with a yield point not less than 420 MPa. The fracture surface of samples after impact bending tests at low temperatures was investigated. It was found that the combination of the parameters of lath morphology bainite (fraction, areas average size and length) and the size of structural elements at given tolerance angles of 5 and 15° (indicating the presence or absence of a developed subgrain structure of deformation origin) determine the level of impact work at low temperatures testing.

scholarly journals Sandwich Panels Bond with Advanced Adhesive Films

2019 ◽  
Vol 3 (3) ◽  
pp. 79 ◽  
Author(s):  
Pereira ◽  
Fernandes
Keyword(s):  
Bonding Strength ◽  
Sandwich Structures ◽  
Sandwich Panels ◽  
Adhesive Film ◽  
Bending Tests ◽  
Steel Sheets ◽  
Innovative Solution ◽  
Aeronautical Industry ◽  
Board Industry

Sandwich structures present several advantages, being used in many industries such as the aeronautical industry. In this study, an automated laminating line is employed to manufacture sandwich panels for boards. This work focus on an innovative solution, employing an advanced adhesive film to increase the bonding strength of sandwich structures used for this application. This was used to bond ceramic steel sheets to honeycomb‐cored structures, creating an innovative solution for the board industry. Bending tests were carried to evaluate the performance of the new sandwich solutions and to compare it against a typical one available on the market.

Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

1993 ◽  
Vol 51 ◽  
pp. 1116-1117
Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii
Keyword(s):  
Intermetallic Compound ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Early Stage ◽  
Zinc Bath ◽  
Steel Sheets ◽  
Direct Observations ◽  
Solid Iron ◽  
Iron And Zinc ◽  
Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

2D analysis of magnetic field strength in GO SiFe steel sheets

1998 ◽  
Vol 08 (PR2) ◽  
pp. Pr2-579-Pr2-582 ◽  
Author(s):  
S. Tumanski ◽  
M. Stabrowski
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Steel Sheets
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