CN-118086653-B - Continuous annealing method of chilled plate

CN118086653BCN 118086653 BCN118086653 BCN 118086653BCN-118086653-B

Abstract

The application relates to the technical field of steel preparation, in particular to a continuous annealing method of a cold hard plate. The method comprises the steps of continuously annealing the chilled plate with the set chemical composition and controlling the atmosphere composition of the annealing, wherein the continuous annealing comprises the steps of heating the chilled plate, then soaking, and setting the heating temperature and the soaking temperature according to the annealing time. The control strategy that different annealing temperatures are matched through different annealing times is adopted, namely the continuous annealing speed is low, the continuous annealing time is long, the lower annealing temperature is matched, the continuous annealing speed is high, the continuous annealing time is short, the higher annealing temperature is matched, and therefore stable control of denitrification amount and grain size is achieved, and fluctuation of mechanical properties of a finished product is reduced. The high-nitrogen continuous annealing plate produced by the method can realize that the denitrification amount in the annealing process is controlled to +/-0.0002 weight percent, and meanwhile, the grain size fluctuation is controlled to +/-0.5 grade.

Inventors

FANG YUAN
CHEN BIN
ZHOU JIAN
XU HAIWEI
YU MENG
BAO CHENGREN
MO ZHIYING
LI HAIXU
YANG SHIYONG
WU ZHIGUO
SUN CHAOFAN
SONG HAO
SHI YUNGUANG
DONG WENLIANG
WANG ZHENWEN
ZHU GUOSEN
ZENG LI

Assignees

首钢集团有限公司

Dates

Publication Date: 20260512
Application Date: 20240329

Claims (1)

1. A method for continuously annealing a high nitrogen cold hard plate, the method comprising: continuously annealing the chilled plate with the set chemical composition, and controlling the atmosphere composition of the annealing, wherein the continuous annealing comprises: heating the chilled plate, soaking, and setting the heating temperature and the soaking temperature according to the annealing time; Performing quick cooling on the soaked cooling hard plate, and controlling the quick cooling temperature to be 380-420 ℃; aging the rapidly cooled cold hard plate, and controlling the aging temperature to be 320-360 ℃; the annealing atmosphere comprises hydrogen and nitrogen, wherein the content of the hydrogen is 3-6 wt%; The set chemical components comprise N, al, nb, V, ti and B, wherein the content of N is 0.008-0.020 wt%, the content of Al is less than or equal to 0.05 wt%, and the total content of Nb, V, ti and B is less than or equal to 0.01 wt%; said setting the temperature of said heating and the temperature of said soaking according to the time of said annealing, comprising: If the annealing time is 60-120 s, the heating temperature and the soaking temperature are 650-670 ℃; if the annealing time is 40-59 s, the heating temperature and the soaking temperature are 670-690 ℃; And if the annealing time is 30-39 s, the heating temperature and the soaking temperature are 690-710 ℃.

Description

Continuous annealing method of chilled plate Technical Field The application relates to the technical field of steel preparation, in particular to a continuous annealing method of a cold hard plate. Background The high nitrogen component is a chemical component commonly used for a tinplate and a chromeplate for metal packaging, the nitrogen content is generally more than 0.006 wt%, however, the phenomenon of nitrogen content reduction can occur in the continuous annealing process of the high nitrogen component steel in a nitrogen-hydrogen mixed atmosphere, which is called denitrification for short, namely, the nitrogen content in the annealed steel is lower than that before annealing, so that the fluctuation of the nitrogen content of a finished product is often caused, the fluctuation sometimes reaches more than 0.001 wt%, and meanwhile, the grain size is often different, so that the mechanical property of the finished product is fluctuated. Disclosure of Invention The application provides a continuous annealing method of a cold and hard plate, which aims to solve the technical problem that the nitrogen content of the existing high-nitrogen cold and hard plate fluctuates greatly in the continuous annealing process. In a first aspect, the present application provides a continuous annealing method for a cold hard plate, the method comprising: continuously annealing the chilled plate with the set chemical composition, and controlling the atmosphere composition of the annealing, wherein the continuous annealing comprises: and heating the chilled plate, then soaking, and setting the heating temperature and the soaking temperature according to the annealing time. Optionally, the heating temperature and the soaking temperature are set according to the annealing time, and the heating temperature and the soaking temperature are 650-670 ℃ if the annealing time is 60-120 s. Optionally, the heating temperature and the soaking temperature are set according to the annealing time, and the heating temperature and the soaking temperature are 670-690 ℃ if the annealing time is 40-59 s. Optionally, the heating temperature and the soaking temperature are set according to the annealing time, and the heating temperature and the soaking temperature are 690-710 ℃ if the annealing time is 30-39 s. Optionally, the annealing atmosphere comprises hydrogen and nitrogen, wherein the content of the hydrogen is 3-6 wt%. Optionally, the chemical composition comprises N, al, nb, V, ti and B, wherein, The content of N is 0.008-0.020 wt%, the content of Al is less than or equal to 0.05 wt%, and the total content of Nb, V, ti and B is less than or equal to 0.01 wt%. Optionally, heating the cold hard plate, soaking, setting the heating temperature and the soaking temperature of the annealing according to the annealing time, and then rapidly cooling the soaked cold hard plate under the condition of a first set temperature. Optionally, the first set temperature is 380-420 ℃. Optionally, the rapid cooling of the soaked chilled plate further comprises aging the rapidly cooled chilled plate under the condition of a second set temperature. Optionally, the second set temperature is 320-360 ℃. Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages: According to the continuous annealing method of the cold and hard plate, provided by the embodiment of the application, the cold and hard plate is mainly used for improving the product performance through N solid solution strengthening, so that the stability of the N content in a finished product is very important, meanwhile, the grain size is controlled, and the grain size fluctuates in a small range to realize the stability of the final product structure performance. Therefore, aiming at the problem of denitrification and grain size cooperative control of a high-nitrogen-content cold hard plate in a nitrogen-hydrogen mixed atmosphere continuous annealing process, a control strategy that different annealing temperatures are matched with different annealing times is adopted, based on thermodynamic and kinetic conditions of the denitrification process, the lower annealing temperature is adopted when annealing is carried out for a long time, the complete recrystallization is ensured and a tissue with proper grain size is formed while the denitrification is prevented from increasing when annealing is carried out for a long time, the higher annealing temperature is adopted when annealing is carried out for a short time, the large difference between the denitrification amount and the recrystallization temperature is prevented when annealing is carried out for a short time, and meanwhile, the improvement of the heating speed to the recrystallization temperature is considered, and the tissue with proper grain size is formed by the higher annealing temperature. Therefore, the stable control of the denitrification amount and the structure grain si