Effect of Local Heating on the Mechanical Characteristics of Repaired Automotive Panels

2019 ◽  
Vol 56 (4) ◽  
pp. 750-758
Author(s):  
Nicolae Navodariu ◽  
Mihai Branzei ◽  
Robert Ciocoiu ◽  
Ion Ciuca ◽  
Razvan Coman ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Cold Working ◽  
Local Heating ◽  
Thin Sheet ◽  
Heating Time ◽  
Steel Plates ◽  
Maximum Temperature ◽  
Material Microstructure ◽  
Technology Process ◽  
Automotive Panels

Flame straightening is a technology process used to eliminate deformations. This method relies on local heating of the material to correct geometry or damaged parts. In the local automobile services its main use is for repairs of less critical deformed components. The maximum temperature and thermal gradient, heating time, cooling rate and number of heating cycles affect the mechanical properties since local heating can alter material microstructure. The aim of this research was to determine the mechanical characteristics of thin steel plates repaired by local heating associated with plastic deformation (similar to hot working) and cold straightening (similar to local cold working) for automotive side and door panels made of structural steel. Thin sheet plates, 0.9mm thickness, were deformed by impact and repaired by local heating using the flame and induction heating then plastically deformed while hot as well as straightened without heating. The heat repaired samples were studied by light microscopy to determine microstructure change and samples were tensile tested to determine their mechanical characteristics. Local excessive grain growth generates anisotropy, the assembly behaves as a composite material with regions that show significant plastic deformations while others little or no deformations at al. Without procedures adjusted to each material repairs involving heating are to be avoided, cold working should be employed when replacement is not possible.

scholarly journals MATERIALS FOR AUTOMOTIVE INDUSTRY AND THEIR INFLUENCE ON THE DYNAMICS OF A CAR CRASH

2019 ◽  
Vol 25 (2) ◽  
pp. 25-32
Author(s):  
NICOLAE NAVODARIU ◽  
ROBERT CIOCOIU ◽  
OCTAVIAN TRANTE ◽  
VASILE IULIAN ANTONIAC
Keyword(s):  
Automotive Industry ◽  
Mechanical Characteristics ◽  
Cold Working ◽  
Local Heating ◽  
Thin Sheet ◽  
Steel Plates ◽  
Metallic Materials ◽  
Car Crash ◽  
Thin Steel ◽  
Metallic Parts

The aim of this research was to determine the influence of the metallic materials characteristics on the dynamics of a car crash. Another important aspect is that the metallic parts are sometimes repaired after minor accidents and this fact influence strongly the mechanical characteristics and their influence on the dynamics of a car crash. In this paper, we analyze the mechanical characteristics of thin steel plates repaired by local heating associated with plastic deformation (similar to hot working) and cold straightening (similar to local cold working) for automotive side and door panels made of structural steel. Thin sheet plates, 0.9mm thickness, were deformed by impact and repaired by local heating using the flame and induction heating then plastically deformed while hot as well as straightened without heating. The heat repaired samples were studied by light microscopy to determine microstructure change and samples were tensile tested to determine their mechanical characteristics. Local excessive grain growth generates anisotropy, the assembly behaves as a composite material with regions that show significant plastic deformations while others little or no deformations at all. Without procedures adjusted to each material repairs involving heating are to be avoided, cold working should be employed when replacement is not possible.

scholarly journals MATERIALS FOR AUTOMOTIVE INDUSTRY AND THEIR INFLUENCE ON THE DYNAMICS OF A CAR CRASH

2019 ◽  
Vol 25 (2) ◽  
Author(s):  
NICOLAE NAVODARIU ◽  
ROBERT CIOCOIU ◽  
OCTAVIAN TRANTE ◽  
VASILE IULIAN ANTONIAC
Keyword(s):  
Automotive Industry ◽  
Mechanical Characteristics ◽  
Cold Working ◽  
Local Heating ◽  
Thin Sheet ◽  
Steel Plates ◽  
Metallic Materials ◽  
Car Crash ◽  
Thin Steel ◽  
Metallic Parts

<p>The aim of this research was to determine the influence of the metallic materials characteristics on the dynamics of a car crash. Another important aspect is that the metallic parts are sometimes repaired after minor accidents and this fact influence strongly the mechanical characteristics and their influence on the dynamics of a car crash. In this paper, we analyze the mechanical characteristics of thin steel plates repaired by local heating associated with plastic deformation (similar to hot working) and cold straightening (similar to local cold working) for automotive side and door panels made of structural steel. Thin sheet plates, 0.9mm thickness, were deformed by impact and repaired by local heating using the flame and induction heating then plastically deformed while hot as well as straightened without heating. The heat repaired samples were studied by light microscopy to determine microstructure change and samples were tensile tested to determine their mechanical characteristics. Local excessive grain growth generates anisotropy, the assembly behaves as a composite material with regions that show significant plastic deformations while others little or no deformations at all. Without procedures adjusted to each material repairs involving heating are to be avoided, cold working should be employed when replacement is not possible.</p>

scholarly journals Investigations on arc brazing for galvanized heavy steel plates in steel and shipbuilding

2021 ◽  
Author(s):  
Philipp Andreazza ◽  
Andreas Gericke ◽  
Knuth-Michael Henkel
Keyword(s):  
Low Cost ◽  
Thin Sheet ◽  
Steel Structures ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Steel Plates ◽  
Galvanized Steel ◽  
Filler Materials ◽  
Static Tensile ◽  
Brazed Joints

AbstractArc brazing with low-melting copper-based filler materials, which has long been established and standardized in the thin sheet sector, offers numerous advantages in the processing of predominantly electrolytically galvanized steel structures. In steel and shipbuilding, on the other hand, equipment parts made of thick steel sheets are hot-dip galvanized at low cost and with good corrosion-inhibiting properties. Quality welding of such constructions is not possible without special precautions such as removing the zinc layer and subsequent recoating. With regard to greater plate thicknesses, arc brazing was analyzed in these investigations as an alternative joining method with regard to its suitability for practical use. Within the scope of the investigations, CuSi3Mn, CuMn12Ni2, and four different aluminum bronzes were examined on different sheet surface conditions with regard to the geometrical and production parameters. This was carried out by build-up and connection brazing, executed as butt and cross joints. Quasi-static tensile tests and fatigue tests were used to assess the strength behavior. In addition, metallographic analyses are carried out as well as hardness tests. The suitability for multi-layer brazing and the tendency to distortion were also investigated, as well as the behavior of arc brazed joints under corrosive conditions.

Tribological Behavior of Composite Electrodes for Spot Welding

2014 ◽  
Vol 656 ◽  
pp. 3-10
Author(s):  
Ionelia Voiculescu ◽  
Victor Geanta ◽  
Elena Manuela Stanciu ◽  
Mihai Vasile ◽  
Tiberiu Laurian ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Spot Welding ◽  
Mechanical Characteristics ◽  
Local Heating ◽  
Tribological Characteristics ◽  
Strengthening Effect ◽  
Composite Electrodes ◽  
Metallic Elements ◽  
Melted Zone ◽  
Resistance To Deformation

The paper presents some aspects regarding tribological characteristics of composite tops of the electrodes for spot welding. The solution aims to improve the resistance to deformation and high intensity electric current conductibility without loses and excessive local heating. The composite material was obtained by mechanical alloying process, from a mixture of tungsten carbide, chromium, CuNiAl alloy and cooper powder which has been heated in furnace at 1100°C. The embedding process aims to avoid the toxic effects of metallic elements such as Be and Zr, which are usually introduced in cupper alloys for improving the mechanical characteristics. The tribological characteristics and microhardness of the melted zone were measured in order to estimate the strengthening effect obtained by the tungsten carbide presence for different mixture recipe.

scholarly journals Bamboo kraft pulping

2019 ◽  
Vol 6 (4) ◽  
pp. 791 ◽  
Author(s):  
Eraldo Antonio Bonfatti Júnior ◽  
Elaine Cristina Lengowski ◽  
Alan Sulato de Andrade ◽  
Ivan Venson ◽  
Umberto Klock ◽  
...  
Keyword(s):  
Raw Materials ◽  
Basic Density ◽  
Heating Time ◽  
Kraft Pulping ◽  
Raw Material ◽  
Maximum Temperature ◽  
Extractive Content ◽  
Technological Characteristics ◽  
Bambusa Vulgaris ◽  
Pinus Spp

Despite of the wide use worldwide, the industrial potential of bamboo species in Brazil is not much investigated. However, some encouragement to revert this situation was created in last few years. The aim of this research was to evaluate the technological characteristics of the Bambusa vulgaris biomass for the production of pulp by the kraft process. The technological characteristics of the raw material were determined by the basic density, the chemical composition and the morphology of the fibers. The cooking process was carried out with the application of eight charges of active alkali, in 90 minutes of heating time and 60 minutes in the maximum temperature of 170ºC. All analyzes were also executed with the Eucalyptus spp. and the Pinus spp., in order to make a complete comparison among the species Bambusa vulgaris and the two most used raw materials for the pulp production in Brazil. The Bambusa vulgaris presented a higher basic density, lower holocellulose content and a higher total extractive content. Its fibers have intermediate length and wall thickness, similar to the Eucalyptus spp. and the Pinus spp. Considering the kraft pulping process, the species Bambusa vulgaris demonstrated to be easier to delignify besides presenting almost zero reject content and smaller consumption of active alkali. However, the Eucalyptus spp. and the Pinus spp. obtained the best yields, the lowest specific consumption of raw material and better selectivities.

scholarly journals OPTIMAL INDUCTOR DESIGN FOR SURFACE HARDENING OF CYLINDRICAL BILLETS BASED ON NUMERICAL TWO-DIMENSIONAL MODEL

2019 ◽  
pp. 40-50
Author(s):  
Yuliya Edgarovna Pleshivtseva ◽  
Anton Valerjevich Popov ◽  
Mariya Aleksandrovna Popova ◽  
Maxim Yurjevich Derevyanov
Keyword(s):  
Optimal Design ◽  
Induction Heating ◽  
Operation Mode ◽  
Heating Time ◽  
Temperature Fields ◽  
Maximum Temperature ◽  
Design Parameters ◽  
Distributed Parameters ◽  
Heating Installation ◽  
And Control

Contemporary industrial production widely uses induction heating prior to the plastic deformation and heat treatment operations due to the benefits it provides in comparison with other types of heating technologies. In order to increase the efficiency of induction heating units and develop their operation mode, the research should be directed towards new design solutions in optimizing constructive parameters of inductors and control algorithms of heating processes. The main goal of the research is developing the best inductor design, which provides maximum temperature uniformity in the surface layer of the billet at the end of heating time. There has been formulated the problem of the inductor unit optimal design with respect to steel cylindrical billets, which can be solved by using the alternance method of parametric optimization of the systems with distributed parameters. Design parameters of the induction heating installation that include the geometry features and the current of power supply are considered as optimized parameters. Software package FLUX was used for developing 2D numerical model of interrelated magnetic and temperature fields in the process of induction heating to describe the system ‘induction heater - billet’. The results of numeric solution of the problem of optimal design have been analyzed.

Structural Design on a Building Stair by Folded Steel Plates in Civil Engineering

2012 ◽  
Vol 568 ◽  
pp. 76-79
Author(s):  
Sheng Cai Li ◽  
Yong Qian ◽  
Yu Liu
Keyword(s):  
Structural Design ◽  
Mechanical Characteristics ◽  
Civil Engineering ◽  
Structure Design ◽  
Steel Plates ◽  
Construction Technology ◽  
Methods Of Calculation ◽  
Structural Principles

To ensure the safety and the logicality of a structure and to meet the needs by the architectural function and form are the main goals of a structure design. Based on the structural principles of safety, comfort and aesthetics, the mechanical characteristics, the methods of calculation and design, and the key construction technology of the stair by folded steel plates are summarized in this paper combined with the design of a steel stair in Shanghai.

Investigating the Use of Stamped Metal Foils as Bipolar Plates in PEM Fuel Cell Stacks

2008 ◽  
Author(s):  
Rachel T. Backes ◽  
David T. McMillan ◽  
Andrew M. Herring ◽  
John R. Berger ◽  
John A. Turner ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Fuel Cell ◽  
Flow Field ◽  
Thin Sheet ◽  
Pem Fuel Cell ◽  
Bipolar Plate ◽  
Steel Plates ◽  
Bipolar Plates ◽  
Fuel Cell Stack ◽  
Serpentine Flow Field

The process of stamping stainless steel bipolar plates is developed from initial plate design through manufacturing and use in a fuel cell stack. A stamped design incorporating a serpentine flow field for the cathode and an interdigitated flow field for the anode is designed. This bipolar plate consists of only one piece of thin stainless steel sheet. The process of rubber-pad stamping was chosen to reduce shearing of the thin sheet. Dies were designed and made. Stainless steel plates were stamped, but stress were higher than anticipated and die failure was observed. The plates were tested both in-situ and by doing simulated fuel cell testing. Although sealing was an issue due to lack of proper gaskets and endplates, tests determined that the stamped bipolar plates will work in a PEM fuel cell stack. Dies were redesigned to improve durability. Gaskets and endplates were designed to complete the stack construction.

scholarly journals The Effect of Heat Treatment Parameters on Mechanical Characteristics of 10CrMo9-10 Steel Tube Bends / Wpływ Parametrów Obróbki Cieplnej Na Charakterystyki Mechaniczne Łuków Rurowych Ze Stali 10CrMo9-10

2015 ◽  
Vol 60 (4) ◽  
pp. 2971-2976
Author(s):  
M. Cieśla ◽  
R. Findziński ◽  
G. Junak ◽  
T. Kawała
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Mechanical Characteristics ◽  
Low Cycle Fatigue ◽  
Steel Tube ◽  
Material Microstructure ◽  
Factor Conditioning ◽  
Lower Temperature ◽  
Material Durability ◽  
Tempering Time

The purpose of the paper was to analyse the effect of diverse heat treatment parameters (normalising and tempering) on mechanical characteristics of the material used to develop ϕ508x20 tube bends made of the 10CrMo9-10 steel by application of induction heating. The research conducted included tests of basic mechanical properties as well as low cycle fatigue and creep at the temperature of 500°C. With reference to the results thus obtained, it has been established that there is a relationship between mechanical properties of bends and individual features of their microstructure conditional to the heat treatment parameters. Among other conclusions drawn in the research, it has been found that the main structural factor conditioning the mechanical properties of bends was the grain size. Heat treatment parameters characterised by lower temperature and shorter tempering time triggered changes in the material microstructure, such as increased grain comminution. The effects of the said changes included improvement of strength characteristics (Rm, Rp0,2) as well as increased material durability under conditions of fatigue and creep. Main criterion-specific mechanical properties and geometric features of the bends developed conformed with the relevant requirements of reference standards (PN-EN 10216-2, PN-EN 12952).

scholarly journals Numerical and Experimental Evaluation and Heat Transfer Characteristics of a Soft Magnetic Transformer Built from Laminated Steel Plates

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7939
Author(s):  
Eduardo Cano-Pleite ◽  
Andrés Barrado ◽  
Néstor Garcia-Hernando ◽  
Emilio Olías ◽  
Antonio Soria-Verdugo
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Numerical Models ◽  
Subsequent Development ◽  
Steel Plates ◽  
Maximum Temperature ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Anisotropic Thermal Conductivity

The present work evaluates, both experimentally and numerically, the heat transfer characteristics of a 5 kW three-phase transformer built from laminated steel sheets. The transformer is operated at different powers, and its temperature distribution is monitored using 108 thermocouples. The experimental measurements are used firstly to determine the heat dissipated at the core and the windings of the transformer. This information is used as an input for a finite element numerical model, which evaluates the heat transfer characteristics of the transformer. The model proposed in this work simply solves the diffusion equation inside the transformer, accounting for the anisotropic thermal conductivity of the different components of the transformer, together with well-known correlations at its boundaries. The results reveal that the proposed numerical model can correctly reproduce the maximum temperature, the temperature distribution, and the time-evolution of the temperature at specific points of the transformer measured during the experimental campaign. These results are of great use for the subsequent development of transformers of the same type in lab-scale or industrial-scale size and reveal the applicability of simplified numerical models to accurately predict the heat transfer characteristics of this kind of transformers.

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