The thermal expansion of wire drawing diesdiameter has a significant impact on the increase of steel wire diameter. In order to measure the distribution of wire drawing die temperature, drill 4 holes in the wire drawing die and insert thermocouples. The distance between each hole and the steel wire surface is respectively 1.5, 4.5, 11.3, 19.3 mm. The thermal conductivity of mold core and mold sleeve is 97,90 W/mK, respectively. Thermal expansion coefficient are: 4.7 x 10-6 / degrees, 12 x 10-6 / degrees. Lubricants are calcium based SCM 435.

Wire drawing die work half cone Angle 4 degrees~ 10 degrees, drawing speed is 10 ~ 110 m/min. Partial compression rate 11.6% (from 7.90mm to 7.42mm).

Half Angle is 7.5 degrees, the entrance of the wire drawing die wire drawing rate of 110 m/min, wire drawing die temperature within the original 2.5 min grew rapidly and stable 10 min later start, A, B, C, D of each hole temperature: 160150138130 degrees; Surface, 110 degrees.

The increase ratio of wire diameter is defined as h= (d-d)/d * 100, where d is the diameter of the drawing wire and d is the diameter of wiredrawing dies. When h is positive, the diameter of the drawn wire is larger than that of the drawing die. When h is negative, the diameter of the drawn wire is smaller than that of the drawing die. Hd =h-h0. In the production process, the difference between the original diameter of the wire before drawing and the diameter of the stable state is very important, so the diameter increase ratio is defined as hd. In drawing speed 110 m/min, working under the condition of half cone Angle is 7.5 degrees, relationship between hd and quality of wire drawing parameters as follows: the quality of steel wire before 200 kg, with the increase of quality, diameter enlargement ratio gradually increases to 0.1%, quality of steel wire after more than 200 kg of steady at 0.1%.

The temperature of hole A decreases gradually with the increase of the working cone half Angle in the steady state of wire drawing. Work half cone Angle is 4 degreesand 5.5 degreesand 7.5 degreesto 10 degrees, hole respectively A temperature: 175170165160 degrees. The diameter increase ratio was 0.15%, 0.12%, 0.10% and 0.08%, respectively.

Drawing under steady state corresponding,40,70,110 10 m/min, drawing speed, hole are A average temperature: 90120150170 degrees. When the drawing speed is lower than 80 m/min, the diameter ratio increases faster with the increase of speed. When the drawing speed exceeds 80 m/min, the diameter increases slowly as the speed increases. When the drawing speed is 10 m/min, diameter enlargement ratio closer to 0%, when the work is half cone Angle of 10 degrees, the diameter increased more than 0.1%.

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