In view of the problem of insufficient capacity of cooling bed with increasing output of rolling mill products

the through-water cooling unit for rolled bar is installed. Production results show that for HRB335 Φ16 mm hot-rolled ribbed steel bar (/%: 0. 20C

0. 20 〜0. 40Si

0. 4 ~ 1. 2Mn)

with original finishing rolling speed 10. 5 -11.0 m/s

the beginning temperature of steel bar at cooling bed is 1 020 ~ 1 050 °C

the yield

tensile strength and elongation of ribbed bar are respectively 342 MPa

520 MPa and 16. 5% ； and after using through-water cooling system

the finishing rolling speed increases to 11.5 ~ 12. 0 m/s

the beginning temperature of steel bar at cooling bed decreases to 880 ~ 900 °C and at outlet of cooling bed the temperature of bar is 260 °C

the yield

tensile strength and elongation of ribbed bar increase respectively to 360 MPa

556 MPa and 16. 9%

and the productivity of mill increases by 3% - 5%.