The present disclosure relates to a CHQ wire rod that has improved resistance to hydrogen delayed fracture while securing cold forging characteristics by reducing Si content and adding Mo and V, a processed product using the same, and a manufacturing method thereof. In accordance with an aspect of the present disclosure, a CHQ wire rod includes, in percent (%) by weight of the entire composition, C: 0.3 to 0.5%, Si: 0.1 to 0.3%, Mn: 0.5 to 1.0%, at least two or more of Cr: 0.5 to 1.5%, Mo: 0.5 to 1.5%, V: 0.01 to 0.2%, the remainder of iron (Fe) and other inevitable impurities, and the value of the following formula (1) is 3.56 or more.

The present disclosure relates to a CHQ wire rod that has improved resistance to hydrogen delayed fracture while securing cold forging characteristics by reducing Si content and adding Mo and V, a processed product using the same, and a manufacturing method thereof. In accordance with an aspect of the present disclosure, a CHQ wire rod includes, in percent (%) by weight of the entire composition, C: 0.3 to 0.5%, Si: 0.1 to 0.3%, Mn: 0.5 to 1.0%, at least two or more of Cr: 0.5 to 1.5%, Mo: 0.5 to 1.5%, V: 0.01 to 0.2%, the remainder of iron (Fe) and other inevitable impurities, and the value of the following formula (1) is 3.56 or more.

A rolling system includes an induction heater, temperature detectors, a finishing mill, and a power setting calculation device. The power setting calculation device generates a temperature distribution pattern in a plate thickness direction of a steel material at a temperature control position in an upstream side. The power setting calculation device calculates a volume average temperature of the steel material at a temperature control position in a downstream side, at a time when the steel material moves to the temperature control position in the downstream side from the temperature control position in the upstream side, based on the generated temperature distribution pattern. Then, the power setting calculation device calculates an electric power necessary for the induction heater so that the calculated volume average temperature follows a target temperature of the steel material at the temperature control position in the downstream side.

A rolling system includes an induction heater, temperature detectors, a finishing mill, and a power setting calculation device. The power setting calculation device generates a temperature distribution pattern in a plate thickness direction of a steel material at a temperature control position in an upstream side. The power setting calculation device calculates a volume average temperature of the steel material at a temperature control position in a downstream side, at a time when the steel material moves to the temperature control position in the downstream side from the temperature control position in the upstream side, based on the generated temperature distribution pattern. Then, the power setting calculation device calculates an electric power necessary for the induction heater so that the calculated volume average temperature follows a target temperature of the steel material at the temperature control position in the downstream side.

The present invention describes a method of dynamical adjustment for manufacturing a thermally treated steel sheet. The method includes: A. a control step, wherein at least one sensor detects a deviation happening during the thermal treatment, B. a calculation step performed when the deviation is detected during the thermal treatment such that a new thermal path TP.sub.target is determined to reach m.sub.target taking the deviation into account, such calculation step including: 1) a calculation substep, wherein at least two thermal path, TP.sub.x corresponding to one microstructure m.sub.x obtained at the end of TP.sub.x, are calculated based on TT and the microstructure m.sub.i of the steel sheet to reach m.sub.target, 2) a selection substep wherein one new thermal path TP.sub.target to reach m.sub.target is selected, TP.sub.target being chosen from said TP.sub.x and being selected such that m.sub.x is the closest to m.sub.target, C. a new thermal treatment step, wherein TP.sub.target is performed online on the steel sheet.

According to an embodiment of the invention, a rolling equipment includes two coiler furnaces; a plurality of mill stands provided between the two coiler furnaces, the plurality of mill stands being for reverse rolling; and an induction heater provided between the plurality of mill stands, the induction heater implementing a heated temperature increase in a designated reverse rolling or in each reverse rolling, the heated temperature increase being in a hot strip longitudinal direction and width direction. Thus, the hot strip temperature distribution can be improved.

According to an embodiment of the invention, a rolling equipment includes two coiler furnaces; a plurality of mill stands provided between the two coiler furnaces, the plurality of mill stands being for reverse rolling; and an induction heater provided between the plurality of mill stands, the induction heater implementing a heated temperature increase in a designated reverse rolling or in each reverse rolling, the heated temperature increase being in a hot strip longitudinal direction and width direction. Thus, the hot strip temperature distribution can be improved.

Provided is a steel used for chassis parts, etc. of an automobile and, more specifically, to a hot rolled steel plate for an electric resistance welded steel pipe, which shows an excellent weldability in electric resistance welding, and a manufacturing method thereof.

Provided is a steel used for chassis parts, etc. of an automobile and, more specifically, to a hot rolled steel plate for an electric resistance welded steel pipe, which shows an excellent weldability in electric resistance welding, and a manufacturing method thereof.

A high-efficient rolling process for magnesium alloy sheet. The process is a rolling process for rolling billets. Parameters of the rolling process are: the rolling speed of each rolling pass is 1050 m/min, the rolling reduction of each rolling pass is controlled to be 4090%, and both the preheating temperature before rolling and the rolling temperature of each rolling pass are 250450 C. A preparation method for magnesium alloy sheet. The method comprises the steps of: 1) preparing rolling billets; 2) high-efficient hot rolling: controlling the rolling speed of each rolling pass to be 1050 m/min, controlling the rolling reduction of each rolling pass to be 4090%, and controlling both the preheating temperature before rolling and the rolling temperature of the each rolling pass to be 250450 C.; and 3) performing annealing. By means of the rolling process, mechanical performance of the sheet can be also effectively improved, and especially, the strength and ductility of the sheet can be greatly improved.