Measurement of austenite-to-ferrite transformation temperature after multi-pass deformation of steels

1995 ◽  
Vol 194 (1) ◽  
pp. L15-L18 ◽  
Author(s):  
Xiaodong Liu ◽  
Jan Ketil Solberg ◽  
Ragnar Gjengedal
Keyword(s):  
Transformation Temperature ◽  
Ferrite Transformation

Investigation of the Effect of Deformation Stored Energy on the Allotropic Transformation Temperature

2015 ◽  
Vol 812 ◽  
pp. 23-28
Author(s):  
Zsolt Csepeli ◽  
Péter Bereczki ◽  
Balázs Verő ◽  
Ibolya Kardos ◽  
Péter János Szabó
Keyword(s):  
Transformation Temperature ◽  
Strong Relationship ◽  
Allotropic Transformation ◽  
Stored Energy ◽  
Dilatometric Measurement ◽  
Austenite Transformation ◽  
Ferrite Transformation ◽  
Novel Method ◽  
Grade Steel ◽  
Start Temperature

The aim of our investigation was to study the effect of deformation on the start temperature of the austenite-ferrite transformation. The deformation was carried out during cooling before the beginning of the transformation. The transformation start temperature was determined by dilatometric measurement with a Gleeble 3800 thermomechanical simulator. A novel method was developed to study the deformation induced ferrite transformation (DIFT) effect and successful experiments were carried out on S460MC grade steel specimens to determine the effect of the deformation stored energy on the transformation temperature of the austenite. Evaluating the dilatograms a strong relationship was observed between the temperature of the deformation and the austenite transformation start and finish temperatures. Lower deformation temperature resulted finer microstructure after austenite transformation.

scholarly journals AUSTENITE – FERRITE TRANSFORMATION TEMPERATURES OF C MN AL HSLA STEEL

2021 ◽  
Vol 27 (4) ◽  
pp. 207-209
Author(s):  
Peter Prislupčák ◽  
Tibor Kvačkaj ◽  
Jana Bidulská ◽  
Pavol Záhumenský ◽  
Viera Homolová ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Transformation Temperature ◽  
Hsla Steel ◽  
Cooling Rates ◽  
Transformation Temperatures ◽  
Temperature Range ◽  
Dilatometric Method ◽  
Ferrite Transformation ◽  
Final Microstructure ◽  
Thermo Calc Software

The article is aimed to investigate a shift of transformation temperatures of C-Mn-Al HSLA steel with different cooling rates. The transformation temperatures from austenite to ferrite have been determined by dilatometry using thermal-mechanical simulator Gleeble 1500D. To define the start and finishing temperatures of the austenite-ferrite transformation intersectional method was used. Effect of cooling rate on transformation temperature has been evaluated for 0.17, 1, 5, 10, 15, 20, 25°C.s-1. There was found out that rising the cooling rate results in moving transformation temperature range to lower temperatures. The transformation temperatures have been also compared with temperatures calculated using equations of several authors. Some of them have considered cooling rates only. Cooling rates have effect on final microstructure. The effect has been evaluated by measuring hardness (HV10) relating the cooling rates from 0.17 to 25°C.s-1. Increasing cooling rates resulted in increase of hardness. Moreover, Thermo-Calc software was used to determine the Ae3 and Ae1 equilibrium temperatures. Equilibrium transformation temperatures Ae3-Ae1 were higher than experimentally measured by dilatometric method using Gleeble 1500D.

Spinel ferrite transformation for enhanced upgrading nickel grade in laterite ore of various types

2021 ◽  
Vol 163 ◽  
pp. 106795
Author(s):  
Jian-ming Gao ◽  
Wenjie Li ◽  
Shujia Ma ◽  
Zongyuan Du ◽  
Fangqin Cheng
Keyword(s):  
Spinel Ferrite ◽  
Ferrite Transformation ◽  
Nickel Grade ◽  
Laterite Ore

scholarly journals First experimental evidence of the piezoelectric nature of struvite

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jolanta Prywer ◽  
Rafał Kruszyński ◽  
Marcin Świątkowski ◽  
Andrzej Soszyński ◽  
Dariusz Kajewski ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Experimental Evidence ◽  
Heating Rate ◽  
Transformation Temperature ◽  
Room Temperature ◽  
Piezoelectric Coefficient ◽  
Piezoelectric Properties ◽  
Parallel Plates ◽  
Gel Growth ◽  
Growth Technique

AbstractIn this paper, we present the first experimental evidence of the piezoelectric nature of struvite (MgNH4PO4·6H2O). Using a single diffusion gel growth technique, we have grown struvite crystals in the form of plane parallel plates. For struvite crystals of this shape, we measured the piezoelectric coefficients d33 and d32. We have found that at room temperature the value of piezoelectric coefficient d33 is 3.5 pm/V, while that of d32 is 4.7 pm/V. These values are comparable with the values for other minerals. Struvite shows stable piezoelectric properties up to the temperature slightly above 350 K, for the heating rate of 0.4 K/min. For this heating rate, and above this temperature, the thermal decomposition of struvite begins, which, consequently, leads to its transformation into dittmarite with the same non-centrosymmetric symmetry as in case of struvite. The struvite-dittmarite transformation temperature is dependent on the heating rate. The higher the heating rate, the higher the temperature of this transformation. We have also shown that dittmarite, like struvite exhibits piezoelectric properties.

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