Metallographic, Structural and Mechanical Characterization of REM-Containing Fe-30Mn-8Al-1.8C Low Density Steel in As-Cast Condition

MRS Advances ◽  
2018 ◽  
Vol 3 (64) ◽  
pp. 3957-3962
Author(s):  
G.Y. Díaz-Martínez ◽  
I. Mejía ◽  
V. García-García ◽  
A. Bedolla-Jacuinde
Keyword(s):  
Mechanical Properties ◽  
Shape Control ◽  
Research Work ◽  
High Strength Steels ◽  
Microstructural Characterization ◽  
Moderate Increase ◽  
Low Density ◽  
Secondary Phases ◽  
Remarkable Effect ◽  
Cast Condition

ABSTRACTRecently, low-density steels have received increased attention as promising alternatives for automotive applications of the next generation of Advanced High-Strength Steels (AHSS), considering that vehicle´s weight decrease has been the subject of intense interest. It is well-known that the addition of rare earth metals (REM) has a remarkable effect on shape control and the modification of inclusions. Also, REM additions affect the grain size refinement as well as the tendency to form oxides and sulfides. The aim of this research work was to determine the effect of REM (Ce, La) addition on the microstructure and mechanical properties of the Fe-30Mn-8Al-1.8C low-density steel in as-cast condition. In order to clarify the REM effect on the Fe-Mn-Al-C system, non-microalloyed (LD-NM) and REM microalloyed (LD-REM) specimens were examined in detail by means of light optical and scanning electron microscopy for microstructural characterization. In the same way, the primary and secondary phases founded in the studied steels were identified by X-ray diffraction (XRD). Meanwhile, in order to evaluate the mechanical properties, ten microhardness measurements were carried out on the overall bulk by the Vickers hardness testing. In general, the results showed a dendritic refinement effect due to the addition of REM to low-density steel. REM acted as effective inoculants agents which reduced the primary and secondary arm spacing. Also, the strong segregation tendency at the grain boundaries in the liquid phase was limited. XRD profiles revealed the presence of austenite, ferrite, κ and DO3 phases. Low density steel microalloyed with REM showed a moderate increase in hardness compared to the non-microalloyed steel in the as-cast condition.

scholarly journals Microstructural characterization and mechanical properties of spot welded dissimilar advanced high strength steels

2021 ◽  
Author(s):  
Muhammad Sohaib Khan
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Microstructural Characterization ◽  
Advanced High Strength Steels ◽  
Spot Welded

Microstructural characterization and mechanical properties of spot welded dissimilar advanced high strength steels

Effect of boron on the continuous cooling transformation kinetics in a low carbon advanced ultra-high strength steel (A-UHSS)

2012 ◽  
Vol 1485 ◽  
pp. 83-88 ◽  
Author(s):  
G. Altamirano ◽  
I. Mejía ◽  
A. Hernández-Expósito ◽  
J. M. Cabrera
Keyword(s):  
Research Work ◽  
High Strength Steels ◽  
High Strength ◽  
Microstructural Characterization ◽  
Low Carbon ◽  
Transformation Kinetics ◽  
Cooling Rates ◽  
Continuous Cooling Transformation ◽  
Continuous Cooling ◽  
Cct Diagrams

ABSTRACTThe aim of the present research work is to investigate the influence of B addition on the phase transformation kinetics under continuous cooling conditions. In order to perform this study, the behavior of two low carbon advanced ultra-high strength steels (A-UHSS) is analyzed during dilatometry tests over the cooling rate range of 0.1-200°C/s. The start and finish points of the austenite transformation are identified from the dilatation curves and then the continuous cooling transformation (CCT) diagrams are constructed. These diagrams are verified by microstructural characterization and Vickers micro-hardness. In general, results revealed that for slower cooling rates (0.1-0.5 °C/s) the present phases are mainly ferritic-pearlitic (F+P) structures. By contrast, a mixture of bainitic-martensitic structures predominates at higher cooling rates (50-200°C/s). On the other hand, CCT diagrams show that B addition delays the decomposition kinetics of austenite to ferrite, thereby promoting the formation of bainitic-martensitic structures. In the case of B microalloyed steel, the CCT curve is displaced to the right, increasing the hardenability. These results are associated with the ability of B atoms to segregate towards austenitic grain boundaries, which reduce the preferential sites for nucleation and development of F+P structures.

Modeling of the Behavior of an Aluminum Metallic Foam by Both FEM and Experimental Results

2013 ◽  
Vol 773-774 ◽  
pp. 478-487
Author(s):  
Juan Pablo Fuertes ◽  
Rodrigo Luri ◽  
Javier León ◽  
Daniel Salcedo ◽  
Ignacio Puertas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flow Stress ◽  
Material Flow ◽  
Aluminum Foam ◽  
Research Work ◽  
Physical And Mechanical Properties ◽  
Metallic Foam ◽  
Low Density ◽  
Metallic Materials ◽  
Aluminum Foams

Aluminum foams are porous metallic materials which possess an outstanding combination of physical and mechanical properties such as: a high rigidity with a very low density. In this present research work, a study on the upsetting of an aluminum foam (with a density = 0.73 g/cm3) is carried out by employing different compression velocity values. From the results obtained, it is possible to determine the material flow stress for its subsequent use in finite element simulations (FEM). Once the material flow stress has been determined, it will be employed in order to analyze the conformability of several parts by FEM.

Effect of Plastic Deformation on a Dispersion of Omega-Phase and Mechanical Properties of an Al-Cu-Mg-Ag Alloy

2014 ◽  
Vol 922 ◽  
pp. 189-194 ◽  
Author(s):  
Marat Gazizov ◽  
Ivan Zuiko ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Cold Rolling ◽  
High Yield ◽  
Moderate Increase ◽  
Coarse Particles ◽  
Secondary Phases ◽  
Omega Phase ◽  
Precipitation Behavior ◽  
Solution Treated

Effect of cold rolling prior to ageing on a dispersion of secondary phases and mechanical properties at room temperature for an Al-5.6Cu-0.72Mg-0.5Ag-0.32Mn-0.17Sc-0.12Zr (wt. %) alloy, which was solution treated and water quenched initially, was examined. It was shown that cold working leads to significant increase in density of lattice dislocations that induces the formation discrete agglomerates of the θ′-phase on the {100} planes. Strain of 7% provided increased aspect ratio (length to thickness) of plates that leads to moderate increase of strength. Imposing of higher strains leads to increased lattice dislocation density and the formation of deformation-induced boundaries. Precipitation of the coarse particles of secondary phases on these boundaries takes place. The high yield stress (YS) of 535 MPa and ultimate tensile strength (UTS) of 570 MPa, were attained after cold rolling with a reduction of 80% followed by ageing at 190°C for 2 h. The effect of plastic deformation prior to ageing on the precipitation behavior and strengthening of Al-Cu-Mg-Ag alloy is discussed.

Dynamic Material Properties of Stainless Steel and Multiphase High Strength Steels

2008 ◽  
Vol 587-588 ◽  
pp. 941-945 ◽  
Author(s):  
M. Durães ◽  
Nuno Peixinho
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Energy Absorption ◽  
Research Work ◽  
High Strength Steels ◽  
High Strength ◽  
Test Results ◽  
Steel Grades ◽  
Dynamic Material Properties ◽  
Steel Dp600

This work presents results of tensile testing of H400 stainless steel, DP600 and TRIP600 at different strain rates. Mechanical properties were determined from tensile test using flat sheet specimens and recurring to different test techniques: servo-hydraulic machine and a tensile-loading Hopkinson bar. The test results were used to compare different mechanical properties of the tested steels and to validate constitutive equations intended to provide a mathematical description of strain rate dependence, namely the Cowper-Symonds equation. Following previous research work in dynamic material proprieties of multiphase and stainless steel grades, the energy absorption in quasi-static crushing of thin walled section made of the tested materials was subsequently investigated. Crush tests were performed in top-hat and hexagonal section tubes manufactured using laser welding. The experimental results were compared in order to assess the efficiency of the different steel grades for energy absorption.

Mechanical properties and microstructure of low carbon ultra-high strength steels (UHSS) microalloyed with boron

2012 ◽  
Vol 1373 ◽  
Author(s):  
I. Mejía ◽  
A. García de la Rosa ◽  
A. Bedolla-Jacuinde ◽  
J.M. Cabrera
Keyword(s):  
Mechanical Properties ◽  
Research Work ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Tests ◽  
Low Carbon ◽  
Advanced High Strength Steels ◽  
New Family ◽  
Ultra High Strength Steels ◽  
Hot Rolled

ABSTRACTThe aim of this research work is to study the effect of boron addition on mechanical properties and microstructure of a new family of low carbon NiCrVCu advanced high strength steels (AHSS). Experimental steels are thermo-mechanically processed (TMP) (hot-rolled+quenched). Results show that the microstructure of these steels contains bainite and martensite, predominantly, which nucleate along prior austenite grain boundaries (GB). On the other hand, tensile tests reveal that the TMP steels have YS (0.2% offset) of 978 MPa, UTS of 1140 MPa and EL of 18%. On the basis of exhibited microstructure and mechanical properties, these experimental steels are classified as bainitic-martensitic complex phase (CP) advanced ultra-high strength steels (UHSS).

Effect of the Aging Treatment in Micro-Alloyed Steel

2012 ◽  
Vol 1481 ◽  
pp. 55-61
Author(s):  
M. A. Doñu Ruiz ◽  
J. A. Ortega Herrara ◽  
N. López Perrusquia ◽  
V. J. Cortés Suárez ◽  
L. D. Rosado Cruz
Keyword(s):  
Mechanical Properties ◽  
Thermal Treatment ◽  
Solution Treatment ◽  
Indentation Test ◽  
Aging Treatment ◽  
Microstructural Characterization ◽  
Water Quenching ◽  
Secondary Phases ◽  
Electric Induction ◽  
Micro Alloyed Steel

ABSTRACTThis work study the effect on aging thermal treatment on micro-alloyed steels API X70 pipe, microstructure and mechanical properties such a yield strength (Y), hardness (Hv) and Young´s modulus (E) are presented in this work. Thermal treatment consists of two phases: i) The solution treatment introducing samples in a electric induction furnace at 1100 °C for 30 min under argon atmosphere and water quenching, ii) aging process for five temperature in the range between 204 to 650 °C for 30 min of time exposition and water quenching, respectively. The microstructural characterization was examined by optical microscopy and matrix samples aging showed microstructures like acicular ferritic, polygonal ferritic and bainitic-ferritic, and the secondary phases were examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) obtained by SEM evidencing the presence of precipitates composed of vanadium (V), niobium (Nb) and titanium (Ti). The mechanical properties were evaluated by depth sensitive indentation test at the samples aging, the results showed increase of the (Hv) and (E)to the conditions of low temperature aging.

scholarly journals Hot Straining and Quenching and Partitioning of a TRIP-Assisted Steel: Microstructural Characterization and Mechanical Properties

2018 ◽  
Vol 941 ◽  
pp. 704-710
Author(s):  
Edwan Anderson Ariza ◽  
Jonathan Poplawsky ◽  
Wei Guo ◽  
André Paulo Tschiptschin
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Microstructural Characterization ◽  
Atom Probe ◽  
Carbon Partitioning ◽  
Carbon Accumulation ◽  
Processing Route ◽  
Carbide Formation ◽  
Quenching And Partitioning

Advanced high strength steels (AHSS), with yield strengths over 300 MPa and tensile strengths exceeding 600 MPa, are becoming more noticeable in vehicle manufacturing. A novel processing route of a TRIP-assisted steel was developed. Characterization and modelling techniques were used to establish correlations between processing, microstructure and mechanical properties. Quenching and partitioning (Q&P) and a novel process of hot straining (HS) and Q&P (HSQ&P) treatments have been applied to a TRIP-assisted steel in a Gleeble ®3S50 thermo-mechanical simulator. The heat treatments involved intercritical annealing at 800 oC and a two-step Q&P heat treatment with a partitioning time of 100 s at 400 oC. The effects of high-temperature isothermal deformation on the carbon enrichment of austenite, carbide formation and the strain-induced transformation to ferrite (SIT) mechanism were investigated. Carbon partitioning from supersaturated martensite into austenite and carbide precipitation were confirmed by means of atom probe tomography (APT). Austenite carbon enrichment was clearly observed in all specimens, and in the HSQ&P samples it was slightly greater than in Q&P, suggesting an additional carbon partitioning to austenite from ferrite formed by the SIT phenomenon. By APT, the carbon accumulation at austenite/martensite interface was clearly observed. The newly developed combined process is promising as the transformation induced plasticity can contribute to the formability and energy absorption, contributing to fill the gap of the third generation of high-strength steels.

scholarly journals Microstructural characterization and mechanical properties of spot welded dissimilar advanced high strength steels

2021 ◽  
Author(s):  
Muhammad Sohaib Khan
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Microstructural Characterization ◽  
Advanced High Strength Steels ◽  
Spot Welded

Microstructural characterization and mechanical properties of spot welded dissimilar advanced high strength steels

scholarly journals Influence of the Addition of Ni on as-Cast Microstructure of Duplex Fe-Mn-Al-C Lightweight Steel

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1551
Author(s):  
Jaka Burja ◽  
Barbara Šetina Batič ◽  
Tilen Balaško
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Weight Reduction ◽  
Steel Production ◽  
Microstructural Characterization ◽  
Road Transport ◽  
Thermodynamic Calculations ◽  
Low Density ◽  
Duplex Steels ◽  
Cast Microstructure

Lightweight Fe-Mn-Al-C steels have low density, and high mechanical properties, which makes them a possibility for weight reduction in vehicles for road transport. In steel production, as-cast microstructure is an important parameter for further processing. The as-cast microstructure of five lightweight duplex steels was investigated: Fe-15Mn-10Al-0.8C, Fe-15Mn-10Al-1.7Ni-0.8C, Fe-15Mn-10Al-3.9Ni-0.8C, Fe-15Mn-10Al-5.6Ni-0.8C and Fe-15Mn-10Al-8.6Ni-0.8C. The influence of Ni was analysed through thermodynamic calculations and microstructural characterization. The samples were analysed through an optical and electron microscopy. The base microstructure of the studied steel consists of ferrite and austenite. Further investigation showed that the decomposition of austenite was accompanied by the formation of kappa carbides and the B2 ordered phase. The addition of Ni prevented the formation of a lamellar kappa ferrite morphology, but at 5.6 wt.% Ni, the decomposition of austenite was most severe, resulting in a large amount of kappa carbides and a B2 ordered phase.

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