TH92284A - Methods and Mills for Hot Rolled Strips from Silicon Steel to Thin Lab Sheets - Google Patents

Abstract

DC60 This invention relates to a method and plant for the production of hot-rolled silicon steel strips for further processing into fine-grained sheets, such as electrical sheets, where the formed product, in this case thin slabs with a maximum thickness of 120 mm, is subjected to a preliminary heating and subsequent hot-rolling process to determine the desired recrystallization conditions. Under this invention, the tein temperature of the formed product (2) entering the hot-rolling process (9a or 9b) shall be at least 1200 °C, with the good form exceeding 1250 °C, which shall be set by at least one heating stage (3) and one superheating stage (6) as part of the preliminary heating process in order to set the final rolling temperature (Twe). This invention relates to a method and plant for the production of hot-rolled silicon steel strips for further processing into fine-grained sheets, such as electrical sheets, where the formed product, in this case thin slabs with a maximum thickness of 120 mm, is subjected to a preliminary heating and subsequent hot-rolling process to determine the desired recrystallization conditions. The initial heating process and subsequent hot rolling process in order to determine the conditions for recrystallization as desired in this invention shall provide a temperature in the tein of the formed product (2) entering the hot rolling process (9a or 9b) of at least 1200 °C, with the good form being higher than 1250 °C, which shall be set by at least one heating stage (3) and one superheating stage (6) as part of the initial heating process in order to set the temperature of the final rolling stage (Twe).

Claims (11)

1. The process of sheet steel fabrication involves several steps: casting thin sheets of silicon steel alloy; passing the cast sheet through a preheating process; passing the preheated sheet through a high-temperature heating process, thereby increasing the sheet temperature to a receiving temperature of at least 1200°C; transferring the heated sheet to a hot rolling mill with multiple rolling mills and inter-rolling cooling systems; removing spatter during the preheating and hot rolling processes; hot rolling the sheet at the specified speed; using cooling systems to reduce sheet thickness; reducing the sheet temperature to the final rolling temperature; and finally transforming the sheet into a suitable recrystallizing state for further processing into oriented sheets. 2. The method described in Reputation 1, which is characterized by the final rolling temperature (Twe) and final rolling velocity of the rolled workpiece being set to values such that complete recrystallization of the steel does not occur, and the workpiece is cooled after its final pass in the hot rolling process from the final rolling temperature (Twe) to the temperature (Ta), ensuring that the required recrystallization conditions specified at the final hot rolling stage on the basis of strip thickness do not occur. 3. The method specified in Claim 2, which is characterized by the final rolling temperature (Twe) of the rolled workpiece being set to a minimum of 950°C, in the good form exceeding 1000°C, and by the specific good form, after hot rolling, the rolled workpiece being cooled to a maximum temperature (Ta) of 650°C, in the good form below 600°C, and in the specific good form below 450°C within 10 seconds. 4. Any of the methods specified in Claims 1 through 3, which are characterized that during the initial heating phase (3) the temperature of the molded product (2) is set to between 1000 and 1100 °C, and which are characterized that during the subsequent heating phase (6) the temperature is raised to 1250 °C. 5. Any of the methods specified in Claims 1 through 4, which are characterized by the primary heating phase (3) occurring in a gas or oil-heated furnace and the subsequent heating phase (6) occurring in an induction heating phase. 6. Any of the methods specified in claims 1 through 5, which are characterized by the fact that stain removal occurs between the initial heating phase (3) and the overheating phase (6) in the stain remover (5). 7. Any of the methods specified in claims 1 through 6, which are characterized by the fact that additional descaling occurs after the high heating phase (6) in the second descaling phase (8). 8. A plant (1) used to produce hot-rolled strips for further processing into sheets with a specific grain arrangement, such as electrical sheets, from a silicon steel alloy formed product using one of the methods specified in Claims 1 through 7, in which the plant shall consist of a continuous forming plant (1a) used to produce the formed product (2); a temperature setting system (7) for initial heating of the formed product; and a rolling mill (9a or 9b) connected downstream from the temperature setting system (7), in which the temperature setting system (7) and the rolling mill (9) shall feed the formed product (2) into a rolled piece with good recrystallization conditions for the next process at the final rolling temperature (Twe); in which the specific characteristics are The temperature setting system (7) for setting the final rolling temperature (Twe) of the rolled workpiece in the rolling process consists of a preliminary heating phase (3) for initially heating the initial product (2) and a superheating phase (6) for heating the molded product (2) further until the temperature at the tein for entering the hot rolling process is higher than 1200 °C, in good form higher than 1250 °C. 9. A factory as specified in claim 8, which is characterized by the use of cooling equipment (11) to the rolled parts along with the cooling parts to a temperature below 600 °C, in which form the drop is below 450 °C. 10. A factory as specified in either claim 8 or 9, which is characterized by a hot rolling process designed to be a compact finishing rolling process (9a). 11. A plant as specified in Claim 8 or Claim 9, which is characterized by the hot rolling process being designed such that it is divided into at least one initial rolling step and at least one final rolling step. (9b)