Stress affected transformation in low alloy steels – factors limiting prediction of plastic strains

2004 ◽  
Vol 120 ◽  
pp. 615-623
Author(s):  
U. Ahrens ◽  
H. J. Maier ◽  
A.EL.M. Maksoud
Keyword(s):  
Isothermal Transformation ◽  
Heat Treatments ◽  
Low Alloy Steels ◽  
Strain Response ◽  
Plastic Strains ◽  
Transformation Plasticity ◽  
Alloy Steels ◽  
Kinetics Of ◽  
Small Plastic Deformation ◽  
Made In

The present study identifies key material phenomena that limit the predictive capabilities of current approaches employed in modelling heat treatments of steels. Focus is on aspects relating to isothermal transformation in low alloy steels. Specifically, experimental data are presented relating to the effects of small plastic deformation on the kinetics of the phase transformation and on transformation plasticity. In addition, stress-strain response of supercooled austenite prior to transformation, i.e. in the temperature range between the A3-temperature and the martensite start temperature, has been determined experimentally. The data obtained demonstrate that the experimental results are only partially compatible with assumptions made in current models that are employed in modelling of heat treatments of steels.

Grain size effect of austenite on the kinetics of pearlite transformation in low- and medium-carbon low-alloy steels

2015 ◽  
Vol 6 (1) ◽  
pp. 41-44 ◽  
Author(s):  
A. E. Gvozdev ◽  
A. G. Kolmakov ◽  
D. A. Provotorov ◽  
I. V. Minaev ◽  
N. N. Sergeev ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Effect ◽  
Low Alloy Steels ◽  
Grain Size Effect ◽  
Medium Carbon ◽  
Alloy Steels ◽  
Kinetics Of

Precipitation related anomalies in kinetics of phosphorus grain boundary segregation in low alloy steels

2003 ◽  
Vol 51 (14) ◽  
pp. 4025-4032 ◽  
Author(s):  
J Janovec ◽  
A Výrostková ◽  
P Ševc ◽  
J.S Robinson ◽  
M Svoboda ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Boundary Segregation ◽  
Grain Boundary Segregation ◽  
Low Alloy Steels ◽  
Alloy Steels ◽  
Kinetics Of

Kinetics of nitrided layers formation on low-alloy steels in the gas nitriding process

2020 ◽  
Vol 24 (4) ◽  
pp. 31-36
Author(s):  
Grzegorz Wójcik ◽  
Barbara Kucharska ◽  
Piotr Wach
Keyword(s):  
Diffusion Layer ◽  
Nitrided Layer ◽  
Surface Hardness ◽  
Nitriding Process ◽  
Process Time ◽  
Low Alloy Steels ◽  
Two Phase ◽  
Gas Nitriding ◽  
Alloy Steels ◽  
Kinetics Of

The study examined cylindrical samples made of low-alloy structural steel 42CrMo4 (40HM) and 41CrAlMo7 (38HMJ) subjected to the nitriding process at 540oC during 2, 7, 12 and 17 hours. During the first 2 hours of the process, the atmosphere was ammonia, while the rest of the process was carried out in the atmosphere consisting of 50% ammonia and 50% dissociated ammonia. After the process, surface hardness, hardness distribution at the depth of 50 µm from the surface up to the hardness of the core, and microstructure of the nitrided layer produced were examined. It has been shown that along with the extension of the duration of the nitriding process on 40HM steel, the surface thickness of the layer of nitrides increases from 6 µm after 2 hours to 14 µm after 17 hours of the process and this layer has a two-phase structure (+’), while the thickness of the diffusion layer was from 0.15 to 0.44 mm (depending on the process time). In the case of 38HMJ steel, the thickness of the layer of nitrides increased from 1 µm after 2 hours to 9.5 µm after 17 hours. The thickness of the diffusion layer was from 0.08 to 0.35 µm (depending on the process time).

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