scholarly journals Application of color etching to study the microstructure of TRIP steel after laser remelting

2018 ◽  
Vol 90 (12) ◽  
Author(s):  
Daniel Dobras ◽  
Małgorzata Rutkowska-Gorczyca
Keyword(s):  
Light Microscopy ◽  
Trip Steel ◽  
Phase Structure ◽  
Laser Remelting ◽  
Accurate Identification ◽  
Type Steel ◽  
Color Metallography ◽  
Multi Phase ◽  
Qualitative Distinction

TRIP type steels have a multi-phase structure, which includes such phases as: aus-tenite, bainite, ferrite and martensite. The presence of so many co-existing phases creates difficulties in their accurate identification. One of the methods used to identify the components of the microstructure is color metallography. Methods of color met-allography in contrary to some methods of microstructure identification (e.g. TEM, EBSD) are simple to use, cheap and not very time-consuming. However, there are still no detailed recommendations on the use of this method. The paper examines the pos- sibilities of application of colored etching methods, to distinguish the components of the microstructure of the as-received material and the welds of the TRIP type steel. Light microscopy methods were used for the study. The obtained results allow for a qualitative distinction of individual components of the microstructure.

scholarly journals USE OF MULTI-PHASE TRIP STEEL FOR PRESS-HARDENING TECHNOLOGY

2019 ◽  
Vol 25 (2) ◽  
pp. 101 ◽  
Author(s):  
Hana Jirková ◽  
Kateřina Opatová ◽  
Štěpán Jeníček ◽  
Jiří Vrtáček ◽  
Ludmila Kučerová ◽  
...  
Keyword(s):  
Trip Steel ◽  
Physical Simulation ◽  
Isothermal Holding ◽  
High Strength Steels ◽  
High Strength ◽  
Press Hardening ◽  
Passenger Safety ◽  
Ultra High Strength Steels ◽  
New Treatments ◽  
Multi Phase

<p class="AMSmaintext">Development of high strength or even ultra-high strength steels is mainly driven by the automotive industry which strives to reduce the weight of individual parts, fuel consumption, and CO<sub>2</sub> emissions. Another important factor is to improve passenger safety. In order to achieve the required mechanical properties, it is necessary to use suitable heat treatment in addition to an appropriate alloying strategy. The main problem of these types of treatments is the isothermal holding step. For TRIP steels, the holding temperature lies in the field of bainitic transformation. These isothermal holds are economically demanding to perform in industrial conditions. Therefore new treatments without isothermal holds, which are possible to integrate directly into the production process, are searched. One way to produce high-strength sheet is the press-hardening technology. Physical simulation based on data from a real-world press-hardening process was tested on CMnSi TRIP steel. Mixed martensitic-bainitic structures with ferrite and retained austenite (RA) were obtained, having tensile strengths in excess of 1000 MPa.</p>

scholarly journals Metallurgical Aspects of Laser Surface Processing of PM Cr-V Ledeburitic Steel

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Peter Jurči ◽  
Jiři Cejp ◽  
Jan Brajer
Keyword(s):  
Solid Solution ◽  
Light Microscopy ◽  
Retained Austenite ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting ◽  
Surface Processing ◽  
Microstructural Changes ◽  
Type Steel ◽  
Eds Microanalysis

The Vanadis 6 ledeburitic-type steel was laser surface remelted. Microstructural changes and hardness in laser affected material were investigated using light microscopy, SEM, and EDS-microanalysis. It was found that the laser surface melting and subsequent rapid solidifying led to softening of the material, due to presence of retained austenite. The melting of the material begins with the transformation of M7C3-carbide into a liquid and finishes via the dissolution of primary solid solution grains. The solidification proceeded in a reverse manner while the eutectics became often so-called degenerous form.

scholarly journals Multi-phase structure and electrical properties of Bi0.5Li0.5ZrO3 doping K0.48Na0.56NbO3 lead-free piezoelectric ceramics

2018 ◽  
Vol 7 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Xiaoyan Peng ◽  
Boping Zhang ◽  
Lifeng Zhu ◽  
Lei Zhao ◽  
Ruixiao Ma ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Phase Structure ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Multi Phase

scholarly journals A multi-phase model for simulations of galaxy formation

2003 ◽  
Vol 208 ◽  
pp. 273-282 ◽  
Author(s):  
Volker Springel ◽  
Lars Hernquist
Keyword(s):  
Star Formation ◽  
Galaxy Formation ◽  
Phase Structure ◽  
Formation Rate ◽  
Disk Galaxies ◽  
Two Phase ◽  
Star Forming ◽  
Hot Gas ◽  
Feedback Model ◽  
Multi Phase

We discuss SPH simulations of galaxy formation which use a hybrid method to describe a two-phase structure of the star forming ISM on unresolved scales. Our modeling includes radiative cooling, heating due to a UV background, growth of cold clouds embedded in an ambient hot gas, star formation out of cloud material, feedback due to supernovae in the form of thermal heating and cloud evaporation, starbursts that can lead to galactic outflows, and metal enrichment. Our particular model for the treatment of the two-phase structure is based on a modified and extended version of the grid-based approach of Yepes et al. (1997). We discuss the properties of the feedback model and show how it stabilizes star forming disk galaxies and reduces the cosmic star formation rate to a level consistent with current observational constraints.

Multi-phase structure of thermally diffused niobium nitride

1991 ◽  
Vol 27 (2) ◽  
pp. 1291-1294 ◽  
Author(s):  
P. Fabbricatore ◽  
R. Musenich ◽  
M. Occhetto ◽  
R. Parodi ◽  
P. Pompa ◽  
...  
Keyword(s):  
Phase Structure ◽  
Niobium Nitride ◽  
Multi Phase

Study on stress-strain response of multi-phase TRIP steel under cyclic loading

2013 ◽  
Author(s):  
W. J. Dan ◽  
Z. G. Hu ◽  
W. G. Zhang ◽  
S. H. Li ◽  
Z. Q. Lin
Keyword(s):  
Cyclic Loading ◽  
Trip Steel ◽  
Strain Response ◽  
Stress Strain ◽  
Multi Phase

Mechanical Properties of Micro-Alloyed TRIP Steel

2010 ◽  
Vol 654-656 ◽  
pp. 242-245
Author(s):  
Jae Hyuk Jung ◽  
Sun Gil Kim ◽  
Bruno C. De Cooman
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Stress ◽  
Microstructure Evolution ◽  
Trip Steel ◽  
Multi Phase

The micro-alloying concepts have been widely used as a way to optimize the microstructure evolution and improve mechanical properties of conventional constructional steels. In the current study, the effect of micro-alloying on the properties of a multi-phase TRIP steel is analyzed. The micro-alloying of TRIP steel was found to lead to an increase of the yield stress rather than the tensile strength. A physical metallurgical explanation of the effect is proposed.

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