| 摘要 |
PURPOSE:To reduce energy consumption and equipment cost for continuous water hardening and annealing by cooling a heated low carbon steel strip to a predetermined cooling start temp. followed by water hardening, overaging at a specified temp. and cooling to room temp. CONSTITUTION:Steel strip 1 is heated to about 700 deg.C and passed through tank 2 filled with warm water of above 40 deg.C at a running speed of 60-500 m/min to cool and harden strip 1. The temp. of strip 1 is measured with thermometer 5 and fed back to controller 4. The temp. of the warm water in tank 2 is measured with thermometer 5 and inputted into controller 4. The temps. are compared in controller 4, and pumps 6, 7 are driven to inject cold water or drain warm water so that the temp. of strip 1 is regulated to a quenching end point of 230-500 deg.C. Strip 1 is overaged at 230-500 deg.C for 0.5-5 min and cooled to room temp. Thus, reheating equipment and energy for overaging are made unnecessary. |
