A control valve for adjusting the cross-sectional area of flow in at least one pipe, in particular for highly dynamic control of the coolant volume for cooling sections in rolling mills, includes a valve body, at least one valve seat and a positioning actuator configured for modifying the position of the valve body. The positioning actuator includes a linear electric motor in order to achieve reproducible response behavior, short response times and high positioning precision of the control valve.

A method of producing a steel material, wherein when a cooling apparatus having a plurality of cooling sections disposed side by side in a longitudinal direction of a steel material cools the steel material hot worked or cooled/reheated, the steel material is conveyed at a conveyance distance L.sub.o (m) satisfying Equation (1), in one direction along with the longitudinal direction of the steel material, in the cooling apparatus, wherein L.sub.o is defined as conveyance distance (m) of steel material, m is a natural number, and L.sub.h is defined as length (m) of cooling sections in longitudinal direction of steel material:

(m0.20)L.sub.hL.sub.o(m+0.20)L.sub.h(1).

In a steel sheet pile according to the present invention, a carbon equivalent CE.sub.N is 0.260 to 0.500, a structure includes a ferrite, a pearlite, a Widmansttten ferrite, and a precipitate, the precipitate is one or both of Nb carbonitride and V carbonitride, a total number density of the precipitate is 0.10 to 0.30 pieces/m.sup.2, a total area ratio of the ferrite and the pearlite is 70% or more, an area ratio of the Widmansttten ferrite is 1% or more, an average grain size of the ferrite and the pearlite is 10 to 80 m, and a yield strength is 460 MPa or more.

A temperature control apparatus of a hot-rolling mill according to the present invention extracts a high-frequency component, a medium-frequency component, and a low-frequency component from a deviation between a calculated value or a measured value of a material temperature in a temperature managing position set on an outlet side of the hot-rolling mill and a given temperature target value. The temperature control apparatus then corrects a reference value of electric power of an induction heating device set to an electric power changing device based on the high-frequency component, corrects a reference value of a cooling water flow rate set to a flow rate changing device based on the medium-frequency component, and corrects a reference value of a roll rotation speed set to a speed changing device based on the low-frequency component.

The invention relates to a hot reversing mill equipped with one or more cooling systems consisting of bars of nozzles spraying an aluminum blank. It also relates to the hot rolling process associated with this hot reversing mill wherein the cooling system serves at least once making it possible to produce aluminum sheets advantageously. It also relates to the process for rolling an AA6xxx series aluminum alloy wherein a blank is cooled during the hot rolling and a sheet obtained with this process. The invention makes it possible to enhance the productivity of reversing mills by enhancing the metallurgical quality and/or the productivity of the other fabrication steps. The invention is particularly useful for providing superior quality 6xxx alloy sheets intended for the automotive industry.

A closed loop temperature control system for use in tandem rolling mills. The closed loop temperature control system uses dynamic information about the temperature of the material moving through the mill to adjust the work rolls to adjust the amount of thickness reduction between the stands to control the temperature of the material as it moves through the mill. In one embodiment, the control system is configured to eliminate or reduce temperature differences across the length of the material as the material moves through acceleration, steady state, and deceleration stages of the rolling process.

A method of cooling a material in a cooling system of a rolling mill using a cooling fluid, which includes the steps of: conveying, by a transportation mechanism, a length of material into the cooling system of a rolling mill; measuring, by a sensor, a speed of the length of material; comparing, by a control system, the measured speed to a setpoint speed, wherein the setpoint speed has a corresponding first flow rate of the cooling fluid; calculating, by the control system, a second flow rate of the cooling fluid based on the comparison, wherein the second flow rate is different from the first flow rate; and applying, to the material in the cooling system, the cooling fluid at the second flow rate.

The invention provides an endless rolling method based on temperature uniformity control, and belongs to the field of iron and steel metallurgy. By optimizing the process path, a new layout mode is adopted, a double heat storage soaking furnace and a descaling box are additionally arranged, transverse and longitudinal bonding magnetic induction heating device is adopted, transverse and longitudinal temperature uniform of the slab in the rolling process is realized, the cross section temperature difference is reduced, and the product quality is improved. On the basis of five-stand arrangement of a traditional finish rolling mill, a rolling mill is additionally arranged to serve as a standby rolling mill, such that on-line non-shutdown change roller of the finish rolling mill is realized. The method of the invention realizes a full-continuous production of production and meets the high-quality development requirements of iron and steel metallurgy, such that traditional cool rolling can be replaced with hot rolling, traditional thick-specification strip can be replaced with high-added-value thin specification strip. There is important significance in the aspects of productivity optimization layout, green manufacturing, intelligent manufacturing and the like.

A X80 pipeline steel with good strain-aging performance comprises (wt. %): C: 0.02-0.05%; Mn: 1.30-1.70%; Ni: 0.35-0.60%: Ti: 0.005-0.020%; Nb: 0.06-0.09%; Si: 0.10-0.30%; Al: 0.01-0.04%; N0.008%; P0.012%; S0.006%; Ca: 0.001-0.003%, and balance iron and unavoidable impurities.

The invention relates to a hot reversing mill equipped with one or more cooling systems consisting of bars of nozzles spraying an aluminum blank. It also relates to the hot rolling process associated with this hot reversing mill wherein the cooling system serves at least once making it possible to produce aluminum sheets advantageously. It also relates to the process for rolling an AA6xxx series aluminum alloy wherein a blank is cooled during the hot rolling and a sheet obtained with this process. The invention makes it possible to enhance the productivity of reversing mills by enhancing the metallurgical quality and/or the productivity of the other fabrication steps. The invention is particularly useful for providing superior quality 6xxx alloy sheets intended for the automotive industry.