scholarly journals Electrochemical Noise Measurements of Advanced High-Strength Steels in Different Solutions

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1232 ◽  
Author(s):  
Marvin Montoya-Rangel ◽  
Nelson Garza-Montes de Oca ◽  
Citlalli Gaona-Tiburcio ◽  
Rafael Colás ◽  
José Cabral-Miramontes ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Noise ◽  
High Strength Steels ◽  
High Strength ◽  
Polynomial Method ◽  
Dual Phase ◽  
Uniform Corrosion ◽  
Advanced High Strength Steels ◽  
Trend Data ◽  
Noise Measurements

Advanced high-strength steels (AHSS), are commonly used in the manufacture of car bodies, as well as in front and rear rails, and safety posts. These components can be exposed to corrosive environments for instance, in countries where de-icing salts are used. In this work, the corrosion behavior of four AHSS steels with dual-phase [ferrite-martensite (DP) and ferrite-bainite (FB)] steels were studied by means of electrochemical noise (EN) measurements according to the ASTM G199-09 standard in NaCl, CaCl2 and MgCl2 aqueous solutions at room temperature. The direct current (DC) trend data from EN were removed by a polynomial method of statistical and spectral analysis. According to the noise resistance (Rn) values obtained for the DP and FB dual-phase steels, both the martensite/bainite content and morphology of the phase constituents have an important effect on the corrosion behavior of these steels. The L.I. (localization index) (0.00054 to 0.15431), skewness (−6.18 to 7.35) and kurtosis (high values 37.15, 74.84 and 106.52) were calculated. In general, the results indicated that the main corrosion process is related to uniform corrosion. Corrosion behavior of AHSS steels exposed in NaCl solution could be related to the morphology of the phase constituents exposed in NaCl, CaCl2 and MgCl2 solutions.

Niobium Containing Advanced High Strength Steels for Automotive Applications – Processing, Microstructure, and Properties

2013 ◽  
Vol 773-774 ◽  
pp. 325-335 ◽  
Author(s):  
Debanshu Bhattacharya
Keyword(s):  
Automotive Industry ◽  
Fuel Efficiency ◽  
High Strength Steels ◽  
High Strength ◽  
Dual Phase ◽  
Trip Steels ◽  
Advanced High Strength Steels ◽  
Energy Absorbing ◽  
Bake Hardenability ◽  
Very High

Two major drivers for the use of advanced steels in the automotive industry are fuel efficiency and increased safety performance. Fuel efficiency is mainly a function of weight of steel parts, which in turn, is controlled by gauge and design. Safety is determined by the energy absorbing capacity of the steel used to make the part. All of these factors are incentives for the automobile manufacturers to use Advanced High Strength Steels (AHSS) to replace the conventional steels used to manufacture automotive parts in the past. AHSS is a general term used to describe various families of steels. The most common AHSS is the dual-phase steel that consists of a ferrite-martensite microstructure. These steels are characterized by high strength, good ductility, low tensile to yield strength ratio and high bake-hardenability. Another class of AHSS is the complex-phase or multi-phase steel which has a complex microstructure consisting of various phase constituents and a high yield to tensile strength ratio. Transformation Induced Plasticity (TRIP) steels is another class of AHSS steels finding interest among the U.S. automakers. These steels consist of a ferrite-bainite microstructure with significant amount of retained austenite phase and show the highest combination of strength and elongation, so far, among the AHSS in use. High level of energy absorbing capacity combined with a sustained level of high n value up to the limit of uniform elongation as well as high bake hardenability make these steels particularly attractive for safety critical parts and parts needing complex forming. A relatively new class of AHSS is the Quenching and Partitioning (Q&P) steels. These steels seem to offer higher ductility than the dual-phase steels of similar strengths or similar ductility as the TRIP steels at higher strengths. Finally, martensitic steels with very high strengths are also in use for certain parts. The most recent initiative in the area of AHSS is the so-called 3rd Generation AHSS. These steels are designed to fill the region between the dual-phase/TRIP and the Twin Induced Plasticity (TWIP) steels with very high ductility at strength levels comparable to the conventional AHSS. Enhanced Q&P steels may be one method to achieve this target. Other ideas include TRIP assisted dual phase steels, high manganese steels and higher carbon TRIP type steels. In this paper, some of the above families of advanced high strength steels for the automotive industry will be discussed with particular emphasis on the role of niobium.

Application of Advanced Multiphase Steels in Crashworthiness Structures: Experimental Study and Constitutive Equations

2006 ◽  
Vol 514-516 ◽  
pp. 579-583 ◽  
Author(s):  
Nuno Peixinho ◽  
António Pinho
Keyword(s):  
Constitutive Equations ◽  
Tensile Testing ◽  
High Strength Steels ◽  
High Strength ◽  
Experimental Program ◽  
Dual Phase ◽  
Strain Rates ◽  
Trip Steels ◽  
Advanced High Strength Steels ◽  
Steel Grades

This work presents results of tensile testing of advanced high strength steels of interest for crashworthy structures: Dual-Phase and TRIP (Transformation Induced Plasticity) steels. The improvements in vehicle crashworthiness observed in recent years have been closely linked to advanced high-strength steels that are currently being produced or in process of development. Amongst these, Dual-Phase and TRIP steels have presented excellent properties for use in crashworthy structures. For these steel grades an understanding of material behaviour at relevant strain rates is needed as well as constitutive equations suitable for use in analytic and numerical calculations. For that purpose an experimental program of tensile testing was performed in a range of strain rates of interest for crashworthiness problems: 0.0001 /s to 1000 /s. The test results were used to compare material properties and to evaluate the Cowper-Symonds constitutive equation and a modified version. Crush tests were performed at different speeds for top-hat and hexagonal tubes manufactured using laser welding and the results discussed in view of energy absorption.

Influence of Microalloying Elements Ti and Nb on Recrystallization during Annealing of Advanced High-Strength Steels

2016 ◽  
Vol 879 ◽  
pp. 217-223 ◽  
Author(s):  
Marion Bellavoine ◽  
Myriam Dumont ◽  
Josée Drillet ◽  
Philippe Maugis ◽  
Véronique Hebert
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Solute Drag ◽  
Dual Phase ◽  
Comparative Efficiency ◽  
Advanced High Strength Steels ◽  
Steel Grades ◽  
Cold Rolled ◽  
Microalloying Elements ◽  
Predominant Effect

Microalloying elements Ti and Nb are commonly added to high-strength Dual Phase steels as they can provide efficient means for additional strengthening due to grain refinement and precipitation strengthening mechanisms. In the form of solute elements or as fine carbonitride precipitates, Ti and Nb are also expected to have a significant effect on the microstructural changes during annealing and especially on recrystallization kinetics. The present work investigates the influence of microalloying elements Ti and Nb on recrystallization in various cold-rolled Dual Phase steel grades with the same initial microstructure but different microalloying contents. Using complementary experimental and modeling approaches makes it possible to give some clarifications regarding both the nature of this effect and the comparative efficiency of Ti and Nb on delaying recrystallization. It is shown that niobium is the most efficient micro-alloying element to impede recrystallization and that the predominant effect is solute drag.

The Draw-Bend Fracture Test and Its Application to Dual-Phase and Transformation Induced Plasticity Steels

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Ji Hyun Sung ◽  
Ji Hoon Kim ◽  
R. H. Wagoner
Keyword(s):  
Shear Fracture ◽  
High Strength Steels ◽  
High Strength ◽  
High Energy ◽  
Tensile Failure ◽  
Dual Phase ◽  
Transformation Induced Plasticity ◽  
Advanced High Strength Steels ◽  
Energy Product ◽  
Dp Steels

Unpredicted sheet forming failures of dual-phase (DP) steels can occur in regions of high curvature and with little apparent necking. Such failures are often referred to as “shear fractures”. In order to reproduce such fractures in a laboratory setting, and to understand their origin and the inability to predict them, a novel draw-bend formability (DBF) test was devised using dual displacement rate control. DP steels from several suppliers, with tensile strengths ranging from 590 to 980 MPa, were tested over a range of rates and bend ratios (R/t) along with a TRIP (transformation induced plasticity) steel for comparison. The new test reliably reproduced three kinds of failures identified as types 1, 2, and 3, corresponding to tensile failure, transitional failure, and shear fracture, respectively. The type of failure depends on R/t and strain rate, and presumably on the initial specimen width, which was constant in this study. Two critical factors influencing the lack of accurate failure prediction were identified. The dominant one is deformation-induced heating, which is particularly significant for advanced high strength steels because of their high energy product. Temperature rises of up to 100 deg. C were observed. This factor reduces formability at higher strain rates, and promotes a transition from types 1 to 3. The second factor is related to microstructural features. It was significant in only one material in one test direction (of 11 tested) and only for this case was the local fracture strain different from that in a tensile failure. Alternate measures for assessing draw-bend formability were introduced and compared. They can be used to rank the formability of competing materials and to detect processing problems that lead to unsuitable microstructures.

scholarly journals Investigation Effect of Spring Back on Bending Test of (DP590) Dual Phase Steel

2018 ◽  
Vol 2 (6) ◽  
pp. 55-62
Author(s):  
Muhamad Sani Buang ◽  
Keyword(s):  
Sheet Metal ◽  
Dual Phase Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Bending Test ◽  
Dual Phase ◽  
Spring Back ◽  
Factors Affecting ◽  
Advanced High Strength Steels ◽  
Fitting In

: The use of advanced high strength steels as a metal in sheet metal forming in automotive industry currently has been increased where Advanced High Strength Steel (AHSS) especially Dual Phase (DP590) Steels have gained a great attention due to a combination of high strength and good formability. However, one of the major constraints in forming AHSS is the occurrence of high spring back caused by elastic relaxation after loading, which causes illness-fitting in part assembly and geometric deviation of the intended design. Spring back is the main problem of defect that occurs at sheet metal after the bending process which creates problems for the parts during the assembly. This paper presents an investigation the effect of spring back on bending test of Dual Phase Steel (DP590). Punch travel and thickness are among factors affecting the spring back behavior. Various parameter value; punch radius (5mm), die radius (5mm), die gap (70mm), thickness of specimen 1mm and 2mm, punch travel/stroke (25%, 50%, 75%, 100%) from 20 mm depth, punch speed (2mm/min) and Orientation of sheet cutting, which is in rolling (00°), diagonal (45°) and transverse (90°). From the analysis of V-bending test punch travel, thickness and orientation of sheet cutting are significant factor that affecting the spring back phenomena. The result form this experiment could be useful for design engineers and manufacturing engineers to make improvement of predict the spring back behavior and also to understanding the material properties of AHSS in order to eliminate spring back and achieve good final product.

Modeling of C-Mn Chromium Containing Steel to Produce DP600 through Thin Slab Direct Rolling

2010 ◽  
Vol 638-642 ◽  
pp. 3502-3507
Author(s):  
M. Wagih ◽  
M. Shahtout ◽  
A. Kady
Keyword(s):  
Grain Size ◽  
High Strength Steels ◽  
High Strength ◽  
Production Costs ◽  
Dual Phase ◽  
Austenite Grain Size ◽  
Advanced High Strength Steels ◽  
Steel Grades ◽  
Direct Rolling ◽  
Part Complexity

The design of new steel grades and microstructures is mostly motivated by the necessity of steel industry to process always better suited high strength steel with low production costs. Automotive customers are asking for more steel options to meet increased specifications for strength, crash worthiness, energy absorption, part complexity, and dent resistance. To meet these requirements, new developed types of steel known as Advanced High-Strength Steels (AHSS) were introduced (e.g.: DP steel "Dual Phase", TRIP steel "Transformation Induced Plasticity",…etc). This paper presents a case study for producing DP600 dual phase steel in EZDK company through building up an integrated model to predicting both final austenite grain size after finishing rolling and the final ferrite grain size after cooling.

Characterization of Metallurgical Transformations in Multi-Phase High Strength Steels by Barkhausen Noise Measurement

2007 ◽  
Vol 539-543 ◽  
pp. 4283-4288
Author(s):  
Aurélie Hug-Amalric ◽  
Xavier Kleber ◽  
Jacques Merlin ◽  
Hélène Petitgand ◽  
Philip Meilland
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Residual Austenite ◽  
Noise Measurement ◽  
Barkhausen Noise ◽  
Dual Phase ◽  
Magnetic Barkhausen Noise ◽  
Noise Measurements ◽  
Multi Phase

The potentialities of using the magnetic Barkhausen noise measurement in characterization of metallurgical transformations have been highlighted in multi-phase High Strength (HS) steels. This kind of steels are composed of different metallurgical constituents, such as ferrite, bainite, martensite or residual austenite. Recently, we found that it was possible to assess the proportion of phases in ferrite-martensite steels and in industrial Dual-Phase steels too. In this work, we show that the Barkhausen noise measurements can be also suitable to follow bainitic transformation in a TRIP steel.

Application of Dual-Phase and TRIP Steels on the Improvement of Crashworthy Structures

2005 ◽  
Vol 502 ◽  
pp. 181-188 ◽  
Author(s):  
Nuno Peixinho ◽  
N. Jones ◽  
António Pinho
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Tensile Tests ◽  
Dual Phase ◽  
Strain Rates ◽  
Trip Steels ◽  
Advanced High Strength Steels ◽  
Steel Grades ◽  
Determination Of Parameters

The improvements in vehicle crashworthiness observed in recent years have been closely linked to advanced high-strength steels that are currently being produced or in process of development. Amongst these, Dual-Phase and TRIP (Transformation Induced Plasticity) steels have presented excellent properties for use in crashworthy structures. For these steel grades an understanding of material behaviour at relevant strain rates is needed as well as constitutiv eequations suitable for use in analytic and numerical calculations. In this study the crashworthiness of thin-walled sections made of Dual-Phase and TRIP steels was investigated. Tensile tests were performed at different strain rates in a range of interest for crashworthiness problems. The results allowed the determination of parameters of Cowper-Symonds equation. Crush tests were performed at different speeds for top-hat and hexagonal tubes manufactured using laser welding. The experimental results were compared with numerical simulations obtained with LS-DYNA software. The influence of different material parameters on the accuracy of the simulations was examined.

scholarly journals Study of Diffusible Behavior of Hydrogen in First Generation Advanced High Strength Steels

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 782
Author(s):  
Dwaipayan Mallick ◽  
Nicolas Mary ◽  
V. S. Raja ◽  
Bernard Normand
Keyword(s):  
Diffusion Coefficients ◽  
First Generation ◽  
High Strength Steels ◽  
High Strength ◽  
Specimen Thickness ◽  
Dual Phase ◽  
Complex Phase ◽  
Advanced High Strength Steels ◽  
Permeation Studies ◽  
Dp Steels

This study deals with microstructural influence on the H permeation behavior of Dual-Phase (DP) and Complex Phase (CP) steels using electrochemical permeation studies. The H diffusion coefficients in DP steels (DP800: 1.65 × 10−10 m2·s−1, DP1000: 1.58 × 10−10 m2·s−1) are half of that found in CP steels (3.07 × 10−10 m2·s−1).The banded microstructure along the specimen thickness and higher C content of the DP led to high H diffusivity of DP steels. The lower total H concentration along with a higher fraction of H was present in the stronger traps in CP steels suggest a better HE resistance of this steel. The H distribution in the specimens was non-uniform, with a higher H concentration speculated near the charging surface.

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