Effects of RE on Critical Cooling Rate of Bearing-B Steel

2012 ◽  
Vol 535-537 ◽  
pp. 761-763 ◽  
Author(s):  
Yi Sheng Zhao ◽  
Xin Ming Zhang ◽  
Zhi Guo Gao
Keyword(s):  
Phase Change ◽  
Cooling Rate ◽  
Experimental Results ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
The Law

The law of phase change of bearing-B steel during continual cooling was studied by adopting dilatometer. The CCT curves of bearing-B steel were drawn, and the effects of RE on critical cooling rates were studied. The experimental results show that the start temperatures of martensite TM was decreased from 438 to 404°C. The critical cooling rate was simultaneously decreased from 33 to 15°C/s.

Critical Cooling Rate for the Glass Formation of Fe80-XCoxP13C7 Alloy

2013 ◽  
Vol 745-746 ◽  
pp. 799-808
Author(s):  
Kai Xu ◽  
Yan Wang ◽  
Qiang Li
Keyword(s):  
Amorphous Alloy ◽  
Cooling Rate ◽  
Thermodynamic Data ◽  
Glass Formation ◽  
Amorphous Alloys ◽  
Experimental Results ◽  
Bulk Amorphous Alloy ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
Dta Curves

In this work, the critical cooling rate Rc for glass formation of a series of Fe80-xCoxP13C7 (x = 0, 5, 10, 15, 20 at.%) alloys was determined by means of constructing CCT curves using Uhlmanns method. The calculated critical cooling rates for x = 0, 5, 10, 15, 20 at.% are 621, 441, 548, 894, 922 K/s, respectively. These results well coincide with the maximum diameters of Fe80-xCoxP13C7 amorphous alloys determined by experiments varying with the content of Co. The calculated Rc was also on the reasonable order of magnitudes. In addition, the values of three common GFA criterions of Trg, ΔTx and γ were calculated according to the thermodynamic data determined from DSC and DTA curves of Fe80-xCoxP13C7 (x = 0, 5, 10, 15, 20 at.%) bulk amorphous alloy. The validity of these GFA criterions in the series of Fe80-xCoxP13C7 (x = 0, 5, 10, 15, 20 at.%) alloys were investigated and it was pointed out that these three GFA criterions were not able to explain the experimental results of the maximum diameters of Fe80-xCoxP13C7 amorphous alloys varying with the content x of Co.

scholarly journals Development of Precipitation Hardening Parameters for High Strength Alloy AA 7068

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 918
Author(s):  
Julia Osten ◽  
Benjamin Milkereit ◽  
Michael Reich ◽  
Bin Yang ◽  
Armin Springer ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cooling Rate ◽  
Maximum Yield ◽  
High Strength ◽  
Tensile Tests ◽  
Age Hardening ◽  
Scanning Calorimetry ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
Kinetics Of

The mechanical properties after age hardening heat treatment and the kinetics of related phase transformations of high strength AlZnMgCu alloy AA 7068 were investigated. The experimental work includes differential scanning calorimetry (DSC), differential fast scanning calorimetry (DFSC), sophisticated differential dilatometry (DIL), scanning electron microscopy (SEM), as well as hardness and tensile tests. For the kinetic analysis of quench induced precipitation by dilatometry new metrological methods and evaluation procedures were established. Using DSC, dissolution behaviour during heating to solution annealing temperature was investigated. These experiments allowed for identification of the appropriate temperature and duration for the solution heat treatment. Continuous cooling experiments in DSC, DFSC, and DIL determined the kinetics of quench induced precipitation. DSC and DIL revealed several overlapping precipitation reactions. The critical cooling rate for a complete supersaturation of the solid solution has been identified to be 600 to 800 K/s. At slightly subcritical cooling rates quench induced precipitation results in a direct hardening effect resulting in a technological critical cooling rate of about 100 K/s, i.e., the hardness after ageing reaches a saturation level for cooling rates faster than 100 K/s. Maximum yield strength of above 600 MPa and tensile strength of up to 650 MPa were attained.

Method for Estimating the Critical Cooling Rate for Glass Formation from Isothermal TTT Data

2007 ◽  
Vol 336-338 ◽  
pp. 1874-1877 ◽  
Author(s):  
Dong Mei Zhu ◽  
Wan Cheng Zhou ◽  
Chandra S. Ray ◽  
Delbert E. Day
Keyword(s):  
Cooling Rate ◽  
Glass Formation ◽  
Lithium Disilicate ◽  
Nucleating Agent ◽  
Cooling Rates ◽  
Continuous Cooling Transformation ◽  
Critical Cooling Rate ◽  
Continuous Cooling ◽  
Transformation Curve ◽  
Continuous Cooling Transformation Curve

A method is proposed for estimating the critical cooling rate for glass formation and continuous cooling transformation curve (CCT) from isothermal TTT data. The critical cooling rates and CCT curves for a group of lithium disilicate glasses containing different amount of Pt as nucleating agent estimated through this method are compared with the experimentally measured values and it shows this method can give a reasonable estimation.

scholarly journals Effect of Strain on Transformation Diagrams of 100Cr6 Steel

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 326 ◽  
Author(s):  
Rostislav Kawulok ◽  
Ivo Schindler ◽  
Jaroslav Sojka ◽  
Petr Kawulok ◽  
Petr Opěla ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Uniaxial Compression ◽  
Martensite Formation ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
Transformation Diagrams ◽  
Kinetics Of

Based on dilatometric tests, the effect of various values of previous deformation on the kinetics of austenite transformations during the cooling of 100Cr6 steel has been studied. Dilatometric tests have been performed with the use of the optical dilatometric module of the plastometer Gleeble 3800. The obtained results were compared to metallographic analyses and hardness measurements HV30. Uniaxial compression deformations were chosen as follows: 0, 0.35, and 1; note that these are true (logarithmic) deformations. The highly important finding was the absence of bainite. In addition, it has been verified that with the increasing amount of deformation, there is a further shift in the pearlitic region to higher cooling rates. The previous deformation also affected the temperature martensite start, which decreased due to deformation. The deformation value of 1 also shifted the critical cooling rate required for martensite formation from the 12 °C/s to 25 °C/s.

scholarly journals Combinatorial measurement of critical cooling rates in aluminum-base metallic glass forming alloys

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naijia Liu ◽  
Tianxing Ma ◽  
Chaoqun Liao ◽  
Guannan Liu ◽  
Rodrigo Miguel Ojeda Mota ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Cooling Rate ◽  
Laser Heating ◽  
Glass Forming Ability ◽  
Rapid Screening ◽  
Composition Effect ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
Glass Forming ◽  
Aluminum Base

AbstractDirect measurement of critical cooling rates has been challenging and only determined for a minute fraction of the reported metallic glass forming alloys. Here, we report a method that directly measures critical cooling rate of thin film metallic glass forming alloys in a combinatorial fashion. Based on a universal heating architecture using indirect laser heating and a microstructure analysis this method offers itself as a rapid screening technique to quantify glass forming ability. We use this method to identify glass forming alloys and study the composition effect on the critical cooling rate in the Al–Ni–Ge system where we identified Al51Ge35Ni14 as the best glass forming composition with a critical cooling rate of 104 K/s.

The effect of cooling rate on crystallization behavior and tensile properties of CF/PEEK composites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Guangming Dai ◽  
Lihua Zhan ◽  
Chenglong Guan ◽  
Minghui Huang
Keyword(s):  
Cooling Rate ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystalline Polymer ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Cooling Rates ◽  
Control Range ◽  
Temperature Range ◽  
Transverse Tensile

Abstract In this study, the differential scanning calorimetry (DSC) tests were performed to measure the nonisothermal crystallization behavior of carbon fiber reinforced polyether ether ketone (CF/PEEK) composites under different cooling rates. The characteristic parameters of crystallization were obtained, and the nonisothermal crystallization model was established. The crystallization temperature range of the material at different cooling rates was predicted by the model. The unidirectional laminates were fabricated at different cooling rates in the crystallization temperature range. The results showed that the crystallization temperature range shifted to a lower temperature with the increase of cooling rate, the established nonisothermal crystallization model was consistent with the DSC test results. It is feasible to shorten the cooling control range from the whole process to the crystallization range. The crystallinity and transverse tensile strength declined significantly with the increase of the cooling rate in the crystallization temperature range. The research results provided theoretical support for the selection of cooling conditions and temperature control range, which could be applied to the thermoforming process of semi-crystalline polymer matrixed composites to improve the manufacturing efficiency.

An Ultrafast Vitrification Method for Cell Cryopreservation

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Fengmin Su ◽  
Nannan Zhao ◽  
Yangbo Deng ◽  
Hongbin Ma
Keyword(s):  
Thin Film ◽  
Cooling Rate ◽  
Experimental Results ◽  
Low Concentration ◽  
Temperature Range ◽  
Thin Film Evaporation ◽  
Film Evaporation ◽  
A Cell ◽  
Cryoprotective Solution ◽  
Ultrafast Cooling

Ultrafast cooling is the key to successful cell vitrification cryopreservation of lower concentration cryoprotective solution. This research develops a cell cryopreservation methodology which utilizes thin film evaporation and achieves vitrification of relatively low concentration cryoprotectant with an ultrafast cooling rate. Experimental results show that the average cooling rate of dimethylsulfoxide (DMSO) cryoprotective solution reaches 150,000 °C/min in a temperature range from 10 °C to −180 °C. The ultrafast cooling rate can remarkably improve the vitrification tendencies of the cryoprotective solution. This methodology opens the possibility for more successful cell vitrification cryopreservation.

Effects of Rare Earths on Structural Transformation of Heavy Rail Steel

2011 ◽  
Vol 194-196 ◽  
pp. 237-242
Author(s):  
Cheng Jun Liu ◽  
Ya He Huang ◽  
Mao Fa Jiang
Keyword(s):  
Cooling Rate ◽  
Incubation Period ◽  
Rare Earths ◽  
Rail Steel ◽  
Vacuum Induction Furnace ◽  
Critical Cooling Rate ◽  
The Stability ◽  
Heavy Rail ◽  
Electronic Microscope ◽  
Heavy Rail Steel

Clean heavy rail steel was prepared by the process of vacuum induction furnace smelting, forge work and rolling. Effects of Rare earths (RE) on phase transformation and microstructure of heavy rail steel were investigated by thermal simulation machine, metallographic microscope and scanning electronic microscope. Thermal simulate tests indicate that, RE can move the C curve of pearlite transformation to lower right, prolong the incubation period of pearlite and improve the stability of undercooled austenite. The minimum incubation period of pearlite transformation is increased from 24s to 30s by RE. Furthermore, RE can decrease the critical cooling rate of pearlite transformation from 1°C•s-1to 0.5°C•s-1and the critical cooling rate of quenching from 15°C•s-1to 13°C•s-1. Additionally, RE can fine the annealing and anormalizing pearlite notably. The pearlite laminae distance of heavy rail steel added RE is decreased by 12.9% (annealing) and 13.3% (normalizing), respectively.

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