The temperature curves of chill and metal mold are shown in Fig. 1 and Fig. 2 respectively.

In about 18 minutes, the inner temperature of the cold iron rises rapidly to 700 ° C, and the outer temperature rises to 100 ° C. at this moment, the temperature gradient of the cold iron is the largest, and the temperature gradient is about 600 ° C; then the cold iron temperature rises slowly, and the inner temperature of the cold iron rises to the highest 830 ° C in 240 minutes, and the temperature difference between the two sides of the cold iron drops to 250 ° C The temperature decreases slowly, and the temperature difference between cold iron and steel decreases to 150 ° C in 360min.

The inner temperature of the metal mold reaches 650 ° C in about 18 min, the outer temperature of the metal mold rises from 50 ° C to 100 ° C, and the temperature difference between the two sides of the metal mold reaches 550 ° C, which reaches the maximum value of the whole temperature measurement stage; with the temperature measurement, the temperature on both sides of the metal mold rises slowly, and the inner temperature of the metal mold reaches the maximum of 650 ° C in 240 min, and the temperature difference between the two sides of the metal mold reaches 550 ° C The temperature difference between the two sides is 250 ° C, and then the temperature of the inner and outer chill decreases slowly, and the temperature difference between the two sides of the metal mold drops to about 170 ° C, which is basically constant.

(1) In the whole process of temperature measurement, the temperature changes of cold iron and metal mold are basically the same;

(2) In the whole temperature measurement stage, the temperature change of the metal mold is less than that of the chill;

(3) In the early stage of temperature measurement, the temperature difference between the two sides of the chill is larger than that of the metal mold, and the chill shows strong chilling capacity;

(4) With the temperature measurement, the cooling capacity of the chill decreases,

(5) The temperature difference between the two sides of the metal mold can be maintained at 170 ° C for a long time until the end of the temperature measurement. Compared with the cold iron, the metal mold has a stronger cooling capacity;

(6) The cooling condition of the inner side of the test block is not as good as that of the outer side.