scholarly journals Influence of Transformation Plasticity on the Distortion of Carburized Quenching Process of Cr-Mo Steel Ring.

1999 ◽  
Vol 48 (7) ◽  
pp. 733-739 ◽  
Author(s):  
Shigeru YAMANAKA ◽  
Takayuki SAKANOUE ◽  
Toshikazu YOSHII ◽  
Tatsuo INOUE
2006 ◽  
Vol 118 ◽  
pp. 369-374 ◽  
Author(s):  
Dong Ying Ju ◽  
Wei Min Zhang ◽  
Y. Matsumoto ◽  
Ryuji Mukai

The objective of this paper is to extend the capability of analyzing the time dependence and coupling of temperature, stress and strain effects on the macroscopic and microscopic structures subjected to quenching, and to introduce a theory of the kinetic of the phase transformation. Strain due to phase transformation, transformation plasticity and thermal expansion are the dominant factors that need to be included in the simulation of a quenching process. The evolution of the microstructure also influences the constitutive equations. In particular, as the temperature changes from the high to phase transformation, temperature and then room temperature, the stress-strain relationship changes from elastic-plastic strain. Therefore, in order to obtain a high strength and ductility in carbon steels, transformation plasticity often has a major effect in increasing of the residual stress during quenching process. In this paper, we measured temperature change and distortion occurring during the quenching process of a carbon steel(SCr420) by thermal simulation machine (Gleeble 1500) are used to determine the parameter of transformation plasticity due to the generation of martensite. The modeling of martensitic transformation plasticity is also verified by using of computational simulation of the quenching process.


2004 ◽  
Vol 120 ◽  
pp. 489-497
Author(s):  
R. Mukai ◽  
D.-Y. Ju

Predictions of deformation, residual stresses and hardness after heat treatment of gears by numerical simulation are very useful to determine optimum condition to decrease the distortion of machinery parts. In this paper, simulation on carburizing quenching of a helical gear made of carbon steel SCr420 was carried out using three-dimensional coupled analysis based on thermo-mechanical theory considering phase transformation. The expansion and latent heat due to phase transformation at various carburizing conditions were measured by TMA and DSC to determine the thermal physical properties of SCr420 carbon steel. The influence of the transformation plasticity strain on deformation, residual stress and hardness of a gear was clarified in the simulation. The accuracy of simulation also is verified by the comparison between the experimental data and the simulated result of the distortion and residual stress. From the predicted results, improvement of the hardness and strength on surface of the gear due to the carburizing-quenching process can be verified.


2004 ◽  
Vol 120 ◽  
pp. 481-488
Author(s):  
C. Franz ◽  
G. Besserdich ◽  
V. Schulze ◽  
H. Müller ◽  
D. Löhe

The simulation of manufacturing processes is more and more becoming an important tool in simultaneous engineering. The aim is to cut the time necessary for development and to optimise processes by simulation of the complete manufacturing chain. The field of heat treatment offers a large variety of applications for the use of simulation tools. Heat treatment of steels always includes the development of residual stresses and distortions. The geometry of the part, the composition of the material, the heat treatment process as well as the initial state of the part interact with each other in complex ways and have an influence on the distortion of the part. Using simulation the temporal development of temperature, phases, stresses and distortions while quenching as well as the residual stress distribution and distortion after quenching can be calculated. Transformation plasticity has been proved to be very important for heat treatment simulation. Three steels with identical contents of alloying elements but different carbon contents of 0.2, 0.5 and 0.8 wt.-% were analysed. The transformation plasticity constants for the martensitic transformation under tensile as well as compressive stresses were determined by quenching hollow specimen with nitrogen. Distortions and residual stresses were examined experimentally with cylinders made out of the three steels. Additionally, simulations of the quenching process of the cylinders were taken into account in the analysis of the experimental findings.


2007 ◽  
Vol 345-346 ◽  
pp. 915-918 ◽  
Author(s):  
Tatsuo Inoue ◽  
Tomohiro Tanaka ◽  
Dong Ying Ju ◽  
Ryuji Mukai

Mechanism of transformation plasticity (TP) is discussed from continuum mechanics viewpoint, and derivation of TP law from the unified thermo-mechanical and transformation plasticity constitutive equation. Result of identified TP coefficient for a chromium steel (JIS SCr420) by use of multi-functional testing machine is introduced as one of the material data together with other data to the simulation of a quenching process by use of newly developed code COSMAP. The simulated distribution of temperature, phases and stress/distortion are compared with the experimentally measured values to verify the accuracy.


2012 ◽  
Vol 27 (6) ◽  
pp. 1024-1028 ◽  
Author(s):  
Zhengtao Duan ◽  
Yanmei Li ◽  
Mingya Zhang ◽  
Minghan Shi ◽  
Fuxian Zhu ◽  
...  

2020 ◽  
Vol 15 (S359) ◽  
pp. 391-395
Author(s):  
Sebastian F. Sánchez ◽  
Carlos Lopez Cobá

AbstractWe summarize here some of the results reviewed recently by Sanchez (2020) comprising the advances in the comprehension of galaxies in the nearby universe based on integral field spectroscopic galaxy surveys. In particular we explore the bimodal distribution of galaxies in terms of the properties of their ionized gas, showing the connection between the star-formation (quenching) process with the presence (absence) of molecular gas and the star-formation efficiency. We show two galaxy examples that illustrates the well known fact that ionization in galaxies (and the processes that produce it), does not happen monolitically at galactic scales. This highlight the importance to explore the spectroscopic properties of galaxies and the evolutionary processes unveiled by them at different spatial scales, from sub-kpc to galaxy wide.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2080
Author(s):  
Cuihong Hou ◽  
Luyi Li ◽  
Lishuang Hou ◽  
Bingbing Liu ◽  
Shouyu Gu ◽  
...  

Yellow phosphorus slag (YPS) is a typical industrial solid waste, while it contains abundant silicon micronutrient required for the growth of rice. The key scientific problem to use the YPS as rice fertilizer is how to activate the slag efficiently during the phosphorite reduction smelting process. In this work, an alkaline rice fertilizer from the activated YPS was successfully prepared to use the micronutrients. Thermodynamic analyses of SiO2-CaO, SiO2-CaO-Al2O3, and SiO2-CaO-Al2O3-MgO systems were discussed to optimize the acidity for reduction smelting. Results showed that the reduction smelting followed by the water quenching process can realize the reduction of phosphorite and activation of YPS synchronously. Ternary acidity m(SiO2)/(m(CaO) + m(MgO)) of 0.92 is suitable for the reduction smelting and activation of the slag. After smelting, the molten YPS can be effectively activated by water quenching, and 78.28% P, 90.03% Ca, and 77.12% Si in the YPS are activated, which can be readily absorbed by the rice roots. Finally, high-strength granular rice fertilizers with a particle size of Φ2–4 mm were successfully prepared from the powdery nitrogen-phosphorus-potassium (NPK) and activated YPS mixture.


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