scholarly journals Effect of Intercritical Annealing and Austempering on the Microstructure and Mechanical Properties of a High Silicon Manganese Steel

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1448 ◽  
Author(s):  
Mattia Franceschi ◽  
Luca Pezzato ◽  
Claudio Gennari ◽  
Alberto Fabrizi ◽  
Marina Polyakova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Intercritical Annealing ◽  
High Strength ◽  
Xrd Analysis ◽  
Tensile Tests ◽  
Manganese Steel ◽  
Microstructure And Mechanical Properties ◽  
Martensitic Microstructure ◽  
Steel Grades ◽  
High Silicon

High Silicon Austempered steels (AHSS) are materials of great interest due to their excellent combination of high strength, ductility, toughness, and limited costs. These steel grades are characterized by a microstructure consisting of ferrite and bainite, accompanied by a high quantity retained austenite (RA). The aim of this study is to analyze the effect of an innovative heat treatment, consisting of intercritical annealing at 780 °C and austempering at 400 °C for 30 min, on the microstructure and mechanical properties of a novel high silicon steel (0.43C-3.26Si-2.72Mn wt.%). The microstructure was characterized by optical and electron microscopy and XRD analysis. Hardness and tensile tests were performed. A multiphase ferritic-martensitic microstructure was obtained. A hardness of 426 HV and a tensile strength of 1650 MPa were measured, with an elongation of 4.5%. The results were compared with those ones obtained with annealing and Q&T treatments.

scholarly journals Effect of the Austempering Process on the Microstructure and Mechanical Properties of 27MnCrB5-2 Steel

2017 ◽  
Vol 62 (2) ◽  
pp. 643-651 ◽  
Author(s):  
A. Morri ◽  
L. Ceschini ◽  
M. Pellizzari ◽  
C. Menapace ◽  
F. Vettore ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Room Temperature ◽  
Tensile Tests ◽  
Impact Tests ◽  
Microstructure And Mechanical Properties ◽  
Martensitic Microstructure ◽  
Elongation To Failure ◽  
Upper Bainite ◽  
Austempering Temperature

AbstractThe effect of austempering parameters on the microstructure and mechanical properties of 27MnCrB5-2 steel has been investigated by means of: dilatometric, microstructural and fractographic analyses; tensile and Charpy V-notch (CVN) impact tests at room temperature and a low temperature.Microstructural analyses showed that upper bainite developed at a higher austempering temperature, while a mixed bainitic-martensitic microstructure formed at lower temperatures, with a different amount of bainite and martensite and a different size of bainite sheaf depending on the temperature. Tensile tests highlighted superior yield and tensile strengths (≈30%) for the mixed microstructure, with respect to both fully bainitic and Q&T microstructures, with only a low reduction in elongation to failure (≈10%). Impact tests confirmed that mixed microstructures have higher impact properties, at both room temperature and a low temperature.

Microstructure and Mechanical Properties of AA5483 after Combination of ECAP and Hydrostatic Extrusion SPD Processes

2014 ◽  
Vol 59 (1) ◽  
pp. 163-166 ◽  
Author(s):  
M. Kulczyk ◽  
J. Skiba ◽  
W. Pachla
Keyword(s):  
Mechanical Properties ◽  
Salt Water ◽  
True Strain ◽  
High Strength ◽  
Tensile Tests ◽  
Hydrostatic Extrusion ◽  
Angular Pressing ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
Marine Applications

Abstract Al-Mg alloys of the 5xxx series are strain hardenable and have moderately high strength, excellent corrosion resistance even in salt water, and very high toughness even at cryogenic temperatures to near absolute zero, which makes them attractive for a variety of applications, e.g. in systems exploited at temperatures as low as -270°C, and marine applications. The present study is concerned with the effect of a combination of 2 processes, which generate serve plastic deformation (SPD), equal channel angular pressing (ECAP) and hydrostatic extrusion (HE), on the microstructure and mechanical properties of an alloy that contain Al and Mg. The alloy was subjected to multi-pass ECAP followed by cumulative HE with a total true strain of 5.9. The microstructure of SPD samples was evaluated by transmission and scanning electron microscopy. The mechanical properties were determined by tensile tests and microhardness measurements. The combination of the two processes gave a uniform nanostructure with an average grain size of 70nm. The grain refinement taking place during the SPD processing resulted in the increase of the mechanical strength by 165% (YS) with respect to that of the material in the as- received state. The experiments have shown that the combination of HE and ECAP permits producing homogeneous nanocrystalline materials of large volumes.

scholarly journals Characterization of the Role of Squeeze Casting on the Microstructure and Mechanical Properties of the T6 Heat Treated 2017A Aluminum Alloy

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
S. Souissi ◽  
N. Souissi ◽  
H. Barhoumi ◽  
M. ben Amar ◽  
C. Bradai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Squeeze Casting ◽  
Applied Pressure ◽  
High Strength ◽  
Casting Process ◽  
Tensile Tests ◽  
Scanning Calorimetry ◽  
Microstructure And Mechanical Properties

In this study, the effects of squeeze casting process and T6 heat treatment on the microstructure and mechanical properties of 2017A aluminum alloy were investigated with scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), differential scanning calorimetry (DSC), and microhardness and tensile tests. The results showed that this alloy contained α matrix, θ-Al2Cu, and other phases. Furthermore, the applied pressure and heat treatment refines the microstructure and improve the ultimate tensile strength (UTS) to 296 MPa and the microhardness to 106 HV with the pressure 90 MPa after ageing at 180°C for 6 h. With ageing temperature increasing to 320°C for 6 h, the strength of the alloy declines slightly to 27 MPa. Then, the yield strength drops quickly when temperature reaches over 320°C. The high strength of the alloy in peak-aged condition is caused by a considerable amount of θ′ precipitates. The growth of θ′ precipitates and the generation of θ phase lead to a rapid drop of the strength when temperature is over 180°C.

Microstructure and Mechanical Properties of 6013 Aluminium Alloy Processed by a Combination of ECAP and Preaging Treatment

2016 ◽  
Vol 877 ◽  
pp. 437-443
Author(s):  
Jia Wei Jiang ◽  
Man Ping Liu ◽  
Yang Liu ◽  
Kai Tang ◽  
Zi Bo Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dislocation Density ◽  
Average Length ◽  
High Strength ◽  
Tensile Tests ◽  
Tem Analysis ◽  
Average Dislocation Density ◽  
Angular Pressing ◽  
Microstructure And Mechanical Properties ◽  
Peak Aging

Microstructure and mechanical properties of a 6013 Al-Mg-Si-Cu aluminum alloy processed by a combination of equal channel angular pressing (ECAP) and preaging treatment were comparatively investigated using quantitative X-ray diffraction (XRD) measurements, transmission electron microscopy (TEM) and tensile tests. In addition, the precipitation sequences were obtained by thermodynamic calculations using the FactSage software package. Average grain sizes measured by XRD are in the range 211–501 nm while the average dislocation density is in the range 0.35-1.0 × 1014 m-2 in the deformed alloy. TEM analysis reveals that fine needle β′′ precipitates with an average length of 4-10 nm are uniformly dispersed in the preaging ECAPed alloy. The local dislocation density in this sample is as high as 2.2×1017 m-2. The strength is significantly increased in the preaging-ECAPed samples as compared to that of the undeformed counterparts. The highest yield strength among the preaging ECAPed alloys is 322 MPa. This value is about 1.25 times higher than that (258 MPa) of the static peak-aging sample. The high strength in the preaging ECAPed alloy is suggested to be related to grain size strengthening and dislocation strengthening, as well as precipitation strengthening contributed from both preaging treatment and ECAP deformation.

scholarly journals Adjustment of Mechanical Properties of Medium Manganese Steel Produced by Laser Powder Bed Fusion with a Subsequent Heat Treatment

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3081
Author(s):  
Lena Heemann ◽  
Farhad Mostaghimi ◽  
Bernd Schob ◽  
Frank Schubert ◽  
Lothar Kroll ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Retained Austenite ◽  
Intercritical Annealing ◽  
High Strength ◽  
Manganese Steel ◽  
Manganese Concentration ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Medium Manganese Steel

Medium manganese steels can exhibit both high strength and ductility due to transformation-induced plasticity (TRIP), caused by metastable retained austenite, which in turn can be adjusted by intercritical annealing. This study addresses the laser additive processability and mechanical properties of the third-generation advanced high strength steels (AHSS) on the basis of medium manganese steel using Laser Powder Bed Fusion (LPBF). For the investigations, an alloy with a manganese concentration of 5 wt.% was gas atomized and processed by LPBF. Intercritical annealing was subsequently performed at different temperatures (630 and 770 °C) and three annealing times (3, 10 and 60 min) to adjust the stability of the retained austenite. Higher annealing temperatures lead to lower yield strength but an increase in tensile strength due to a stronger work-hardening. The maximum elongation at fracture was approximately in the middle of the examined temperature field. The microstructure and properties of the alloy were further investigated by scanning electron microscopy (SEM), hardness measurements, X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and element mapping.

scholarly journals Influence of Intercritical Annealing on Microstructure and Mechanical Properties of a Medium Manganese Steel

2017 ◽  
Vol 207 ◽  
pp. 1803-1808 ◽  
Author(s):  
Marco Haupt ◽  
Aniruddha Dutta ◽  
Dirk Ponge ◽  
Stefanie Sandlöbes ◽  
Monika Nellessen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Intercritical Annealing ◽  
Manganese Steel ◽  
Microstructure And Mechanical Properties ◽  
Medium Manganese Steel
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