scholarly journals Prediction of Hardness for Partially Quenched Boron Steel Using Quench Factor Analysis

2015 ◽  
Vol 3 (5) ◽  
pp. 259-265 ◽  
Author(s):  
J. Y. Choi ◽  
J. H. Kim ◽  
D. H. Ko ◽  
P. K. Seo ◽  
D. C. Ko ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Boron Steel ◽  
Quench Factor Analysis

Evolution of Quench Factor Analysis: A Review

2010 ◽  
pp. 991-991-30
Author(s):  
Patricia Mariane Kavalco ◽  
Lauralice C. F. Canale
Keyword(s):  
Factor Analysis ◽  
Quench Factor Analysis

Hardness Prediction of Tailor Rolled Blank in Hot Press Forming Using Quench Factor Analysis

2017 ◽  
Vol 729 ◽  
pp. 110-114
Author(s):  
Jae Hong Kim ◽  
Dae Cheol Ko ◽  
Byung Min Kim
Keyword(s):  
Factor Analysis ◽  
Fe Simulation ◽  
Boron Steel ◽  
Rear Side ◽  
Cooling Curves ◽  
Hot Press ◽  
Tailor Rolled Blank ◽  
Side Member ◽  
Press Forming ◽  
Hot Press Forming

This paper aims to predict the hardness of hot formed part for tailor rolled blank (TRB) by the FE-simulation coupled with quenching factor analysis (QFA). Dilatometry test of boron steel is performed at various range of cooling rates from 0.2 to 100°C/s using the dilatometer with forced air cooling system. The dilatometry test provides a hardness data according to cooling curves which are used to determine the material constants (K1~K5) of QFA and the time‒temperature‒property (TTP) diagram of boron steel. Then, FE‒simulation of hot press forming is conducted to predict the cooling curves of hot formed TRB part with a thickness combination of thicker 1.6mm and thinner 1.2mm which is called as rear side member of automotive component. The cooling curves of FE-simulation are applied to predict the hardness of hot formed rear side member using the QFA. Also, experiment of hot press forming is performed to verify the predicted results and to examine the effect of cooling curves on the hardness.

Quench Factor Analysis To Quantify Steel Quench Severity And Its Successful Use In Steel Hardness Prediction

2006 ◽  
Author(s):  
Lauralice C. Franceschini Canale ◽  
Antônio Carlos Canale ◽  
Charles E. Bates ◽  
George E. Totten
Keyword(s):  
Factor Analysis ◽  
Hardness Prediction ◽  
Quench Factor Analysis

Quench Factor Analysis

2019 ◽  
Author(s):  
Rosa L. Simencio Otero ◽  
Patricia M. Kavalco ◽  
Lauralice C. F. Canale ◽  
George E. Totten ◽  
Lemmy Meekisho
Keyword(s):  
Factor Analysis ◽  
Classical Model ◽  
Numerical Procedure ◽  
Rate Sensitivity ◽  
Cooling Curve ◽  
Boundary Structure ◽  
Temperature Property ◽  
Grain Boundary Structure ◽  
The One ◽  
Quench Factor Analysis

One of the steps of the heat treatment process of age-hardenable aluminum alloys is the quenching process in which the alloy is cooled from the solutionizing temperature. The objective is to quench sufficiently fast to avoid undesirable concentration of alloying elements in the defect and grain boundary structure while at the same time not quenching faster than necessary to minimize residual stresses, which may lead to excessive distortion, or cracking. Various studies have been conducted to predict the relative quench rate sensitivity to yield different properties for age-hardenable alloys. Of these different predictive methods, the one that showed the more realistic results is quench factor analysis (QFA) since it involves a correlation of the cooling curve (time–temperature curve) of the cooling process throughout the quenching cycle for the desired cross-section size of interest with a C-curve (Time–Temperature–Property Curve) for the specific alloy of interest. The QFA numerical procedure has evolved since its original introduction. A review of the basic assumptions of the classical QFA model will be provided here, which will include discussion of the various improvements to the classical model that have been proposed over the intervening years since its introduction.

scholarly journals Hardness Prediction in Hot Stamping Process by Local Blank Heating Based on Quench Factor Analysis

Metals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 29
Author(s):  
Jae-Hong Kim ◽  
Dae-Cheol Ko ◽  
Seon-Bong Lee ◽  
Byung-Min Kim
Keyword(s):  
Factor Analysis ◽  
Volume Fraction ◽  
Heating Temperature ◽  
Hot Stamping ◽  
Prediction Method ◽  
Heating Time ◽  
Stamping Process ◽  
Automotive Parts ◽  
Hardness Prediction ◽  
Quench Factor Analysis

Recently, the hot stamping process using local blank heating has been widely used to manufacture lightweight and crashworthy automotive parts. However, the hardness prediction of hot stamped parts produced using local blank heating is difficult because it involves many process variables, such as the heating temperature, heating time, and cooling rate. The purpose of this study was to predict the hardness of hot stamped parts fabricated using local blank heating based on quench factor analysis (QFA). The volume fraction of austenite was measured to consider the phase transformation in the heating stage, and it was expressed by the Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation. Additionally, a dilatometry test was performed to measure the hardness according to the cooling rates, which was used to determine the material constants for QFA. Finite-element simulation was performed to predict the temperature histories during the hot stamping process and the results were used to predict the hardness according to QFA with the JMAK equation. A hot stamping experiment with local blank heating equipment was performed, and the predicted and experimental results were compared for verification of the proposed hardness prediction method.

Precipitation Kinetics Analysis of the Cooling Process Following the Solid Solution Treatment of 7B50 Aluminum Alloy

2017 ◽  
Vol 898 ◽  
pp. 213-222
Author(s):  
Lei Kang ◽  
Yuan Jun Cui ◽  
Gang Zhao ◽  
Ni Tian
Keyword(s):  
Factor Analysis ◽  
Solution Treatment ◽  
Axial Direction ◽  
Avrami Equation ◽  
Hardness Distribution ◽  
Thickness Direction ◽  
Analysis Method ◽  
Precipitation Kinetics ◽  
Thick Plates ◽  
Quench Factor Analysis

Based on the TTP curves of 7050 alloy, and the continuous cooling curves of 7B50 alloy at different positions of Φ70 mm improved Jominy specimen, the hardness distribution along the thickness direction of 7B50 alloy thick plates was analyzed and predicted by means of the isothermal precipitation kinetics and the quench factor analysis method. The results show that when 7050 alloy is isothermal treated at 200°C~400°C, the exponent n in its Johnson-Mehl-Avrami equation is close to 1, which indicates that the nucleation process of new precipitates is stable. In this equation the coefficient k is 7.420E-03 at 350°C, which indicates that the nucleation and growth rates of new precipitates are very fast. The hardness distribution along the axial direction of the improved Jominy specimen of 7B50 alloy is predicted by the quench factor analysis method. When the distance is no more than 65 mm from the spraying surface of the improved Jominy specimen, the deviation between the predicted and measured hardness of 7B50 alloy in T6 temper is less than 5%. The quench factor analysis method is feasible to predict the hardness distribution along the thickness direction of 7B50 alloy thick plates after quenching and aging. When the quench factor analysis method is extended to predict the actual water spray quenching process of 7B50 alloy thick plates, the average cooling rate is 21.6°C/s in the quench sensitive temperature range of this alloy, at 15 mm from the spraying surface of the plate. At the same position, the corresponding quench factor is equal to 6 and the predicted hardness is 187.4 HV which is equivalent 98.5% of the Hmax (the maximum hardness) of 7B50 alloy in T6 temper.

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