The Influence of Temperature on Zinc Abrasion in Deep Drawing Processes

2014 ◽  
Vol 611-612 ◽  
pp. 1039-1046 ◽  
Author(s):  
Peter Sachnik ◽  
Wolfram Volk ◽  
Roland Golle ◽  
Hartmut Hoffmann
Keyword(s):  
Deep Drawing ◽  
High Strength Steels ◽  
High Strength ◽  
Heating System ◽  
Sheet Metals ◽  
Process Stability ◽  
Forming Process ◽  
Whole Process ◽  
Different Temperatures ◽  
The Impact

Due to the development of corrosion-resistant lightweight, todays automotive manufacturers typically use zinc coated sheet metals in the forming process. However, zinc abrasion in industrial presses decreases the process stability and often causes interruption of the whole process. The application of high strength steels leads to a significant increase of the temperature due to the plastic work. So far a detailed, quantitative analysis of the relation between temperature and zinc abrasion is not available. Therefore, this paper examines the impact of the temperature on abrasion behaviour in sheet metal processes. To achieve this, a progressive die was built. The deep drawing stage of this tool is connected to a cooling / heating system in order to obtain a constant temperature during the forming process. A variety of different galvanized sheet metals compared to commonly used tool materials has been tested. For each combination of materials five experiments at different temperatures were performed to determine the effect of the temperature on the zinc abrasion. Applying the method of total reflection x-ray fluorescence (TXRF) the quantity of zinc abrasion was measured. A relation between low temperatures and reduced zinc abrasion can be clearly observed. Industrial experiments revealed that temperature exerts a high influence on the zinc abrasion. The new insights into the impact of the temperature show a significant way to lower the zinc abrasion and therefore increase the process stability in deep drawing processes.

scholarly journals Research on Liquid Forming Process of Nickel Superalloys Thin Sheet Metals

2017 ◽  
Vol 62 (4) ◽  
pp. 2355-2358
Author(s):  
M. Hyrcza-Michalska
Keyword(s):  
Mechanical Properties ◽  
Computer Aided Design ◽  
Best Practice ◽  
Thin Sheet ◽  
High Strength Steels ◽  
High Strength ◽  
Working Fluid ◽  
Nickel Superalloys ◽  
Sheet Metals ◽  
Forming Process

AbstractThe paper presents the study of drawability of thin sheet metals made of a nickel superalloy Inconel type. The manufacturing process of axisymmetric cup – cone and a closed section profile in the form of a circular tube were designed and analyzed. In both cases, working fluid-oil was used in place of the rigid tools. The process of forming liquid is currently the only alternative method for obtaining complex shapes, coatings, and especially if we do it with high-strength materials. In the case of nickel superalloys the search for efficient methods to manufacture of the shaped shell is one of the most considerable problems in aircraft industry [1-5]. However, the automotive industries have the same problem with so-called advanced high-strength steels (AHSS). Due to this, both industrial problems have been examined and the emphasis have been put on the process of liquid forming (hydroforming). The study includes physical tests and the corresponding numerical simulations performed, using the software Eta/Dynaform 5.9. Numerical analysis of the qualitative and quantitative forecasting enables the formability of materials with complex and unusual characteristics of the mechanical properties and forming technology. It has been found that only the computer aided design based on physical and numerical modeling, makes efficient plastic processing possible using a method of hydroforming. Drawability evaluation based on the determination of the mechanical properties of complex characteristics is an indispensable element of this design in the best practice of industrial manufacturing products made of thin sheet metals.

Hot Spline Forming of Ultra-High Strength Steel Gear Drum Using Resistance Heating

2014 ◽  
Vol 622-623 ◽  
pp. 201-206 ◽  
Author(s):  
Kenichiro Mori ◽  
Tomoyoshi Maeno ◽  
Shohei Nakamoto
Keyword(s):  
Deep Drawing ◽  
High Strength Steel ◽  
Side Wall ◽  
High Strength ◽  
Axial Direction ◽  
Resistance Heating ◽  
Sectional Area ◽  
Forming Process ◽  
Cross Sectional ◽  
Ultra High Strength Steel

A hot spline forming process of die-quenched gear drums using resistance heating of a side wall of a cup formed by cold deep drawing and ironing was developed. The side wall having uniform cross-sectional area is resistance-heated by passage of the current in the axial direction, the heated side wall of the drawn cup is ironed and is finally die-quenched. The gear drum was successfully formed and the hardness was between 400 and 500 HV. Not only the formability was improved but also the formed dram was hardly oxidised because of rapid resistance heating.

scholarly journals Experimental Investigation on the Effect of Shot Peening and Deep Rolling on the Fatigue Response of High Strength Fasteners

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1093 ◽  
Author(s):  
Reggiani
Keyword(s):  
Fatigue Life ◽  
Shot Peening ◽  
High Strength Steels ◽  
High Strength ◽  
Experimental Tests ◽  
Published Data ◽  
Deep Rolling ◽  
Beneficial Impact ◽  
The Impact ◽  
Fatigue Life Enhancement

Shot-peening and deep rolling are mechanical surface treatments that are commonly applied to enhance the fatigue performances of components, owing to their capacity to generate compressive residual stresses and induce work hardening. However, literature is still poor of published data concerning the application of these treatments to high strength steels fasteners, although these represent a class of components among the most widespread. In the present work, the impact of deep rolling and shot-peening performed in the underhead radius of two set of fasteners made of 36NiCrMo and 42CrMoV for fatigue life enhancement has been investigated. The experimental tests consisted of six combinations of shot-peening and deep rolling, including the non-treated state. Two test campaigns have been sequentially carried out with different process parameters and treatment sequences. The results always showed a beneficial impact of the deep rolling on fatigue, especially for the 42CrMoV steel. Conversely, the effect of the shot-peening strongly depended on the selected set of parameters, alternatively leading to an improvement or a worsening of the fatigue life in relation to the level of induced surface roughness.

Springback Analysis in Bilayer Material Bending

2017 ◽  
Author(s):  
Chetan P. Nikhare
Keyword(s):  
Fuel Consumption ◽  
Elastic Recovery ◽  
Dissimilar Materials ◽  
High Strength Steels ◽  
Thick Layer ◽  
High Strength ◽  
Geometric Error ◽  
Forming Process ◽  
Tailor Welded Blanks ◽  
Geometric Defect

Exponential increase in the use of auto vehicles, and thus the fuel consumption, which relates to the air pollution, vehicle industry are in a strict environmental regulation from government. Due to which the innovation related to light-weighting is not only an option anymore but became a mandatory necessity to decrease the fuel consumption. To achieve this target, industry has been looking in fabricating components from high strength to ultra-high strength steels. With the usage of these material the lightweight was achieved by reducing a gage thickness. However due to their high strength property often challenges occurred are higher machine tonnage requirement, sudden fracture, geometric defect, etc. The geometric defect comes from elastic recovery of a material, which is also known as a springback. Springback is commonly known as a manufacturing defect due to the geometric error in the part, which would not be able to fit in the assembly without secondary operation or compensation in the forming process. Due to these many challenges, other research route involved is composite material, where light materials can be used with high strength material to reduce the overall vehicle weight. This generally includes, tailor welded blanks, multi-layer material, mechanical joining of dissimilar material, etc. Due to the substantial use of dissimilar materials, these parts are also called as hybrid components. It was noted that the part weight decreases with the use of hybrid components without compromising the integrity and safety. In this paper, a springback analysis was performed considering bilayer metal. For this two dissimilar materials aluminum and composite was considered as bonded material. This material was then bent in a channel forming set-up. The bilayer springback was compared in different condition like aluminum layer on punch side and then on die side. These results were then compared with the baseline springback of only aluminum thin and thick layer. It was found that the layer, which sees the punch side, matters due to the differences in elastic properties for both material and thus it directly influences the springback.

Investigation of EN AW 5754 Aluminum Alloy’s Formability at Elevated Temperatures

2017 ◽  
Vol 885 ◽  
pp. 98-103 ◽  
Author(s):  
Dávid Budai ◽  
Miklós Tisza ◽  
Péter Zoltán Kovács
Keyword(s):  
Elevated Temperatures ◽  
High Strength Steels ◽  
High Strength ◽  
Carbon Composite ◽  
Alloy Sheet ◽  
High Mass ◽  
Mass Reduction ◽  
Forming Process ◽  
Forming Temperature ◽  
Operating Distance

Nowadays, mass reduction is the most often used term in the automotive industry. Car manufacturers are continuously working on getting ever lighter models than the previous ones, because of the global competition and the rigorous emission rules. A light car has many advantages: lower consumption, better handling, longer operating distance, etc. The emission rules forced the car brands to start new researches to find new solutions for mass reduction. The formula is relatively simple, using lighter or less materials or both and the car will be lighter. In the recent solutions there are three different ways: application of high strength steels, aluminum alloys, and carbon-composite elements. Our investigations are focusing mainly on aluminum, because of its high mass reduction potential. The biggest problem with the aluminum is its low formability. The formability of aluminum is lower than the steel, and it causes problems for the manufacturers. To increase the formability of the aluminum is a hot topic in the research and development area. Forming at elevated temperatures is one of the best solutions to increase the formability of aluminum. The relation between the formability and the forming temperature is not linear, furthermore beyond the optimum forming temperature the formability decreases. We need dozens of investigations to describe the perfect relation, but sometimes a good approximation is enough to form sheet products safely. In our work we investigated the EN AW 5754 aluminum alloy sheet at room temperature, 130°C, 200°C and 260°C. From these tests we could obtain FLC curves of the alloy at different temperatures. Using these curves, the process engineers could find the optimum parameters of their forming process.

Reliability of Burst Limit States for Damaged and Corroded High Strength Pipelines

2006 ◽  
Author(s):  
Marc A. Maes ◽  
Mamdouh M. Salama ◽  
Markus Dann
Keyword(s):  
Limit State ◽  
High Strength Steels ◽  
High Strength ◽  
Crack Arrest ◽  
Limit States ◽  
Lower Strain ◽  
Margin Of Safety ◽  
Normal Strength ◽  
The Impact

High strength steels (X100 and X120) that are being considered for high pressure gas pipelines differ from conventional steels by exhibiting lower work hardening capacity, lower strain to failure and softening of their HAZ. These differences impact burst limit state and tensile limit state, in addition to crack arrest. In this paper, the impact of the variations in mechanical properties on the reliability of pipe limit states involving ductile burst of damaged or corroded pipe is examined. The paper presents the results of burst limit state analysis using state-of-the-art plastic burst models of strain hardening pipe and considering all the uncertainties that impact the margin of safety of pipes subject to internal pressure. Intact pipes, corroded pipes and externally damaged pipes are considered. A case study comparing the differences between normal strength (X60) pipeline and high strength (X100) pipeline is also presented.

scholarly journals Thermal Diffusivity of Traditional and Innovative Sheet Steels

2010 ◽  
Vol 297-301 ◽  
pp. 893-898
Author(s):  
Elena Campagnoli ◽  
Paolo Matteis ◽  
Giovanni M.M. Mortarino ◽  
Giorgio Scavino
Keyword(s):  
Thermal Diffusivity ◽  
Deep Drawing ◽  
Process Model ◽  
Twip Steel ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels

The low carbon steels, used for the production of car bodies by deep drawing, are gradually substituted by high strength steels for vehicle weight reduction. The drawn car body components are joined by welding and the welded points undergo a reduction of the local tensile strength. In developing an accurate welding process model, able to optimized process parameters and to predict the final local microstructure, a significant improvement can be given by the knowledge of the welded steels thermal diffusivity at different temperatures. The laser-flash method has been used to compare the thermal diffusivity of two traditional deep drawing steels, two high strength steels already in common usage, i.e. a Dual Phase (DP) steel and a TRansformation Induced Plasticity (TRIP) steel, and one experimental high-Mn austenitic TWIP (Twinning Induced Plasticity) steel. The low carbon steels, at low temperatures, have a thermal diffusivity that is 4-5 times larger than the TWIP steel. Their thermal diffusivity decreases by increasing temperature while the TWIP steel shows an opposite behaviour, albeit with a lesser slope, so that above 700°C the TWIP thermal diffusivity is larger. The different behaviour of the TWIP steel in respect to the ferritic deep drawing steels arises from its non ferro-magnetic austenitic structure. The DP and TRIP steels show intermediate values, their diffusivity being lower than that of the traditional deep drawing steels; this latter fact probably arises from their higher alloy content and more complex microstructure.

Metallurgical Design of High Strength/High Toughness Steels

2012 ◽  
Vol 706-709 ◽  
pp. 2084-2089
Author(s):  
Andrea di Schino ◽  
Mauro Guagnelli
Keyword(s):  
Impact Toughness ◽  
Yield Strength ◽  
High Strength Steels ◽  
High Strength ◽  
Carbon Steels ◽  
Main Concern ◽  
Microstructural Parameters ◽  
Fine Microstructure ◽  
The Impact ◽  
Strength And Toughness

The proper balance between yield strength, YS, and ductile to brittle transition temperature, DBTT, has been the main concern during development of high strength engineering steels and the effect of microstructure on impact toughness has attracted a great attention during the last decades. In this paper a review concerning the relationship between strength and toughness in steels will be presented and the effect of different microstructural parameters will be discussed, aiming toimprovesuch properties in designingnewhigh strength steels. Complex microstructures, obtained by quenching and tempering (Q&T) and thermo-mechanical (TM) processing are considered. The steels are low/medium carbon steels (C=0.04%-0.40%) with yield strength in the range YS=500-1000 MPa. Results show that the strength and the impact toughness behaviour are controlled by different microstructural parameters and not, as in the case of polygonal ferritic steels, by the same structural unit (the grain size) and that a “fine” microstructure is required in order to achieve high levels of both strength and toughness. The metallurgical design of high strength steels with toughness requirements is discussed using the same approach for both Q&T and TMCP processes.

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