scholarly journals Improvement of microstructure and properties in twin-roll casting 7075 sheet by lower casting speed and compound field

2017 ◽  
Vol 127 ◽  
pp. 325-332 ◽  
Author(s):  
G. Chen ◽  
J.T. Li ◽  
Z.K. Yin ◽  
G.M. Xu
Keyword(s):  
Casting Speed ◽  
Microstructure And Properties ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

scholarly journals Effect of Cooling Rate on Microstructure and Properties of Twin-Roll Casting 6061 Aluminum Alloy Sheet

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1168 ◽  
Author(s):  
Zhen Xu ◽  
Sixue Wang ◽  
Hongbin Wang ◽  
Hua Song ◽  
Shengli Li ◽  
...  
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Cooling Rate ◽  
Alloy Sheet ◽  
Aluminum Alloy Sheet ◽  
6061 Aluminum Alloy ◽  
Microstructure And Properties ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

In this study, a twin-roll casting sheet of 6061 aluminum alloy was cooled using furnace, asbestos, air, wind and water. The effect of cooling rate on the microstructure and properties of twin-roll casting 6061 aluminum alloy sheet were studied. Optical microscope, scanning electron microscope, X-ray diffraction, microhardness tester and universal tensile machine were used to observe the microstructure and properties of twin-roll casting sheet of 6061 aluminum alloy. The results show that the higher the cooling rate, the smaller the grain size of the alloy and the smaller the number of precipitated phases in the matrix. Uniform grain size of the alloy could be obtained at a stable cooling rate. The hardness, tensile strength and elongation of the twin-roll casting sheet increased with cooling rate. Under wind cooling condition, the twin-roll casting sheet demonstrated excellent comprehensive performance, i.e., 88 MPa of yield strength, 178 MPa of tensile strength and 15% of elongation, respectively. A quantitative Hall–Petch relation was established to predict the yield strength of 6061 twin-roll casting sheets with different grain sizes and cooling rate.

scholarly journals Role of Roll Separating Force in High-Speed Twin-Roll Casting of Aluminum Alloys

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 645 ◽  
Author(s):  
Min-Seok Kim ◽  
Hyoung-Wook Kim ◽  
Su-Hyeon Kim ◽  
Shinji Kumai
Keyword(s):  
Aluminum Alloys ◽  
Casting Speed ◽  
High Speed ◽  
Rolling Texture ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Fine Microstructure ◽  
Roll Separating Force ◽  
Twin Roll

The role of the roll separating force in the high-speed twin-roll casting of aluminum alloys was examined. In horizontal-type twin-roll casting, as the casting speed increased upon decreasing the roll separating force, the strip texture changed from a shear and rolling texture to a random texture. Direct temperature measurements during high-speed twin-roll casting showed that the roll separating force played a significant role in maintaining a good contact between the strip and the roll surface. This resulted in a high cooling rate around the roll nip and enabled the fabrication of a sound strip with a fine microstructure. Moreover, the high casting speed and lowered roll separating force gave a band structure consisting of fine globular grains in the mid-thickness region of the strip, which could be considered beneficial in the formation of a well-dispersed center segregation.

Temperature Field and Cast-Rolling Force Prediction during Horizontal Twin-Roll Casting Magnesium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 412-420 ◽  
Author(s):  
Xiao Ping Liang ◽  
Lei Xiao ◽  
Sang Sang Liao ◽  
Bin Jiang
Keyword(s):  
Temperature Field ◽  
Magnesium Alloy ◽  
Process Parameters ◽  
Casting Speed ◽  
Rolling Force ◽  
Pouring Temperature ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Cooling Intensity ◽  
Twin Roll

The control of process parameters in the horizontal twin-roll casting is crucial for the quality of sheet and the continuity of the process. A temperature field coupled with flow field mathematical model was established during the horizontal twin-roll casting of AZ31 magnesium alloy sheet with 1500mm in width and 8mm in thickness in this paper. The temperature field in the casting zone was solved by the software ANSYS. The effect of process factors, such as casting speed, pouring temperature and cooling intensity, on casting zone temperature of different process parameters were studied. Based on the solved temperature field, with the hot roll formula and test data of yield strength, the effect of casting speed, pouring temperature and cooling intensity on cast-rolling force in the cast-rolling zone was also dicussed. The results indicate that the casting speed has the greatest effect upon the temperature field and cast-rolling force, while the pouring temperature is the least. In addition, the value of critical cooling intensity increased with the increase of the casting speed. The quality defect called melt sheet or the leakage phenomenon appear when the cooling intensity is lower than the minimal critical cooling intensity value, and crack or rolling suspended appear if the cooling intensity is higher than the maximal critical cooling intensity value. When the casting speed are 1m/min, 2m/min and 3m/min, the minimal and maximal critical cooling intensity are 500, 1200, 2 000 W/(m2.K) and 2500, 5000, 7500 W/(m2.K) respectively.

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