scholarly journals Precipitation Behavior of AlN Inclusions in Fe-0.5Al-2.0Mn Alloy Under Continuous Unidirectional Solidification Process

2021 ◽  
Vol 8 ◽  
Author(s):  
Nghiem NguyenVan ◽  
Kengo Kato ◽  
Hideki Ono
Keyword(s):  
Solidification Process ◽  
High Strength ◽  
Unidirectional Solidification ◽  
Chemical Compositions ◽  
Precipitation Behavior ◽  
Sheet Steels ◽  
Trip Steels ◽  
Initial Content ◽  
The Stability ◽  
New Generation

Medium Manganese Transformation Induced Plastic (Mn-TRIP) steels are expected to be a new generation of advanced high strength sheet steels due to their excellent balance between material cost and mechanical properties. During the solidification process, AlN precipitates at the grain boundary, which leads to the serious deterioration of hot ductility. However, the precipitation of AlN in Mn-TRIP steel has not been clear. In this study, the chemical compositions, morphology, size distribution, and the precipitation behavior of AlN inclusion in an Fe-0.5Al-2.0Mn alloy were studied under the continuous unidirectional solidification process. The results show that there are two types of nitride inclusions in the Fe-0.5Al-2.0Mn alloy: AlN inclusion and complex inclusion of Al2O3-AlN. The planar sections of most AlN particles are hexagonal. Based on the thermodynamic calculation, it was found that the content of Al has a large effect on the stability of Al2O3 and AlN. When the content of Al increases, the molten iron can be changed from saturated by Al2O3 to saturated by AlN. During the solidification process, the precipitation of Al2O3 inclusions occurred at the beginning of the solidification process. The precipitation of AlN inclusions occurred when the contents of Al and N exceeded the equilibrium value and grew until the end of the solidification. The precipitation conditions of AlN inclusion in the Fe-0.5Al-2.0Mn alloy during the solidification process were discussed. The precipitation and the amount of precipitate of AlN inclusions depend on the initial contents of Al, N, and O. It was found that the precipitation of AlN inclusions can be controlled by reducing the initial content of N to less than 0.0072 mass%.

A New Frontier in Microalloying: Advanced High Strength, Coated Sheet Steels

2005 ◽  
Vol 500-501 ◽  
pp. 27-38 ◽  
Author(s):  
Anthony J. DeArdo ◽  
J.E. Garcia ◽  
Ming Jian Hua ◽  
C. Isaac Garcia
Keyword(s):  
High Strength ◽  
Laboratory Simulation ◽  
Sheet Steels ◽  
Trip Steels ◽  
New Frontier ◽  
Evolution Of Microstructure ◽  
Coated Sheet

TRIP steels containing Mn, Si, Al, Mo, and Nb have been examined using a laboratory simulation of a continuous hot dipped galvanizing line. The evolution of microstructure has been studied as the steel passes through the various stages of CG line processing. Tensile strengths approaching 800 MPa and ductilities approaching 30% have been achieved in the 1.5Mn-0.5Si- 1.0Al-0.015Mo-0.03Nb system.

Effect of Retained Austenite Stability on Mechanical Properties of 590MPa Grade TRIP Sheet Steels

2010 ◽  
Vol 638-642 ◽  
pp. 3374-3379 ◽  
Author(s):  
Hiroshi Matsuda ◽  
Hisata Noro ◽  
Yasunobu Nagataki ◽  
Yoshihiro Hosoya
Keyword(s):  
Mechanical Properties ◽  
Carbon Content ◽  
Retained Austenite ◽  
High Strain ◽  
Sheet Steels ◽  
Trip Steels ◽  
Austenite Stability ◽  
Retained Austenite Stability ◽  
The Stability ◽  
High Work

Industrial low alloy TRIP sheet steels contain blocky and lath-shaped retained austenite. In the present study, transformation behaviour of blocky and lath-shaped retained austenite during straining was investigated to clarify its effect on mechanical properties. Two types of TRIP steels containing almost the same amount but the different morphology of retained austenite were used. A steel containing large amount of lath-shaped retained austenite exhibits superior ductility, and sustains high work-hardenability in a high strain region. On the contrast, a steel containing large amount of blocky retained austenite exhibits low ductility. 　The work-hardenability increased steeply to the maximum at a low strain region, and then reduced in a high strain region. The stability of the blocky austenite has been found to be poor with respected to martensite transformation. The lath-shaped retained austenite remains until a high strain region whereas the blocky retained austenite transformed into martensite in a low strain region. Carbon content was higher in the lath-shaped retained austenite than in the blocky retained austenite. Stability of retained austenite is, however, inexplicable only by the carbon content, and would be affected by the different morphology and the resulting restraint conditions.

The Effect of Texture on the Stability of Retained Austenite in Al-Alloyed TRIP Steels

2011 ◽  
Vol 1296 ◽  
Author(s):  
Kemal Davut ◽  
Stefan Zaefferer
Keyword(s):  
Retained Austenite ◽  
Electron Backscatter Diffraction ◽  
High Strength ◽  
Trip Steels ◽  
Tension And Compression ◽  
Stable Austenite ◽  
Ebsd Technique ◽  
Face Centered ◽  
The Stability ◽  
Backscatter Diffraction

ABSTRACTSteels with transformation induced plasticity (TRIP) offer an excellent combination of high strength and ductility. The transformation of meta-stable austenite into martensite during straining leads to strong local hardening and prevents early localization of strain. Therefore, the mechanical properties of TRIP steels, including the damage resistance depend to a significant extent on the stability of retained austenite. The aim of this study was to evaluate the effect of texture on the stability of retained austenite. In order to compare the changes in both tension and compression the steel was deformed by a micro 3-point-bending device. The texture development upon bending was followed by electron backscatter diffraction (EBSD) technique. Based on a simple analysis using the relation between face centered cube (FCC) and body centered cube (BCC) shear geometries theoretically expected changes of texture components due to deformation are proposed. Using the results of this analysis the observed changes of the austenite texture due to deformation could be distinguished from those due to transformation, by comparing the experimental results with the theoretically expected behavior. From this comparison, austenite grains with “Brass (B) {011} <211>” and “Goss (G) {110} <100>” texture components were found to transform into martensite much easier than differently oriented grains.

scholarly journals Investigation into the Structural, Chemical and High Mechanical Reforms in B4C with Graphene Composite Material Substitution for Potential Shielding Frame Applications

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1921
Author(s):  
Ibrahim M. Alarifi
Keyword(s):  
Composite Material ◽  
Melting Point ◽  
Boron Carbide ◽  
High Strength ◽  
Stir Casting ◽  
High Fracture Toughness ◽  
Chemical Compositions ◽  
High Fracture ◽  
Fabrication Procedure ◽  
Standard Designs

In this work, boron carbide and graphene nanoparticle composite material (B4C–G) was investigated using an experimental approach. The composite material prepared with the two-step stir casting method showed significant hardness and high melting point attributes. Scanning electron microscopy (SEM), along with energy dispersive X-ray spectroscopy (EDS) analysis, indicated 83.65%, 17.32%, and 97.00% of boron carbide + 0% graphene nanoparticles chemical compositions for the C-atom, Al-atom, and B4C in the compound studied, respectively. The physical properties of all samples’ B4C–G like density and melting point were 2.4 g/cm3 density and 2450 °C, respectively, while the grain size of B4C–G was in the range of 0.8 ± 0.2 µm. XRD, FTIR, and Raman spectroscopic analysis was also performed to investigate the chemical compositions of the B4C–G composite. The molding press composite machine was a fabrication procedure that resulted in the formation of outstanding materials by utilizing the sintering process, including heating and pressing the materials. For mechanical properties, high fracture toughness and tensile strength of B4C–G composites were analyzed according to ASTM standard designs. The detailed analysis has shown that with 6% graphene content in B4C, the composite material portrays a high strength of 134 MPa and outstanding hardness properties. Based on these findings, it is suggested that the composite materials studied exhibit novel features suitable for use in the application of shielding frames.

scholarly journals Microstructural effects on fracture toughness of ultra-high strength dual phase sheet steels

2021 ◽  
Vol 802 ◽  
pp. 140631
Author(s):  
D. Frómeta ◽  
N. Cuadrado ◽  
J. Rehrl ◽  
C. Suppan ◽  
T. Dieudonné ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
High Strength ◽  
Dual Phase ◽  
Sheet Steels ◽  
Microstructural Effects

Fundamental Study on Improvement in Frontal Crashworthiness by Application of High-Strength Sheet Steels

1997 ◽  
Author(s):  
Naomitsu Mizui ◽  
Kiyoyuki Fukui ◽  
Nobusato Kojima ◽  
Miyuki Yamamoto ◽  
Yoshiaki Kawaguchi ◽  
...  
Keyword(s):  
High Strength ◽  
Fundamental Study ◽  
Sheet Steels

Detection and In-Field Verification of Potential Pipeline Expansion Due to Low Yield Strength Pipe in High Strength Line Pipe

2010 ◽  
Author(s):  
Jill Braun ◽  
Stuart Clouston
Keyword(s):  
High Resolution ◽  
Yield Strength ◽  
Measurement Errors ◽  
High Strength ◽  
Lessons Learned ◽  
Chemical Compositions ◽  
Line Pipe ◽  
Variable Yield ◽  
Field Verification ◽  
Pipe Joints

On May 21, 2009, the Pipeline & Hazardous Materials Safety Administration (PHMSA) issued an Advisory Bulletin (PHMSA-2009-0148) entitled, “Potential for Low and Variable Yield, Tensile Strength and Chemical Compositions in High Strength Line Pipe” [1] recommending that pipeline operators investigate whether recently constructed pipelines contain pipe joints not meeting the minimum specification requirements (74FR2390). Based on PHMSA’s technical reviews, high resolution deformation tool inspection combined with comprehensive infield verification has been recommended in accordance with the “Interim Guidelines for Confirming Pipe Strength in Pipe Susceptible to Low Yield Strength,” issued by PHMSA in September 2009[2]. Kern River Gas Transmission Company (Kern River) underwent a detailed program of engineering and assessment in order to proactively demonstrate compliance with the interim guidelines. This paper discusses the process, inspection results and infield verifications performed by the pipeline operator. In particular, detailed consideration to the methodology of detection and assessment of potential pipeline expansions is presented with discussion on the special considerations needed for low level anomaly identification, reporting and verification of expansions as defined in the PHMSA guidelines. High resolution caliper analysis approaches developed for this particular application are discussed and appropriate techniques are recommended that consider the effects of possible asymmetry of expansions and impact of other deformations such as ovality. Field verification practices and findings are reviewed in detail with particular focus on the challenges facing the pipeline operator in resolving both tool and in-field measurement errors that can significantly impact the number of identifiable candidate expansions for verification. In conclusion, an overview of the assessment criteria and field activity to comply with the PHMSA interim guidelines are presented along with the lessons learned from the analysis, verification and remediation steps that may assist other pipeline operators as they address these newly established regulatory requirements.

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