Abstract
The influence of the soaking temperature on the occurrence of ear in deep drawing of one-way-and crossway-rolled sheets (both are not intermediate-annealed) is examined. The soaking temperature of the continuouscast 2S slab is changed to 360°C and 490°C, the cold reduction (one-way rolling and cross-way rolling) is changed in the range of 78.5-95.7% and the annealing temperature is changed in 290°C-450°C. The directionality of sheet is examined as follows:
(1) The directionality is detected mainly by measuring the Knoop ratio and the decrement of Harbert pendulum. It is found out from the experiment that the directionality is superior in 45°-direction to the rolling direction in the case that the high soaking temperature and the hard reduction are given and it is superior in 0°, 90°-direction in the case that low soaking temperature and the small reduction are given.
(2) The directionality of the one-way rolled sheet is superior in 45°-direction than that of the cross-wayrolled sheet under the same reduction and heat treatment.
(3) The directionality expressed by the proportion of Knoop ratio "m" and the proportion of Harbert decrement "p" makes the above mentioned facts clear. And the ratio "m" and "p" are in the closed connection with the occurence of ear in deep drawing as mentioned in previous report, so that the earing may be forecast even without the deep drawing test.
(4) The results obtained from the experiment to detect the directionality by the predominant orientation of grain are completely agreed with the results in the ratio "m" and "p". The directionality detected by means of tension test also matches the above mentioned results.
