Production method for inline increase in precipitation toughening effect of Ti microalloyed hot-rolled high-strength steel

Patent metadata

Field	Value
Publication number	US-11384406-B2
Application number	US-201816648773-A
Country	US
Kind code	B2
Filing date	Sep 20, 2018
Priority date	Sep 20, 2017
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

There is provided a production method for on-line improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel, comprising: casting a molten steel with microalloying element Ti added to obtain an ingot; after heating the ingot, subjecting it to rough rolling, finish rolling, laminar cooling and coiling to obtain a hot-rolled coil; after unloading the coil, covering the coil on-line with an insulating enclosure and moving it into a steel coil warehouse along with a transport chain; after a specified period of on-line insulating time, removing the coil from the insulating enclosure, and cooling it to room temperature in air, wherein the microalloying element Ti has a content of ≥0.03 wt %; the coiling is performed at a temperature of 500-700° C.; said covering on-line with an insulating enclosure means each hot-rolled coil is individually covered with an independent, closed insulating enclosure unit within 60 minutes after unloading; the on-line insulating time is ≥60 minutes. The method of the present disclosure is characterized by low cost and high efficiency, and is not affected by surroundings.

First claim

What is claimed is:

1. A production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel, comprising:
casting a molten steel with microalloying element Ti added to obtain an ingot; after heating the ingot, subjecting it to rough rolling, finish rolling, laminar cooling and coiling to obtain a hot-rolled coil; after unloading the hot-rolled coil, covering each of the hot-rolled coil individually with an independent, closed insulating enclosure unit within 60 minutes and moving it into a steel coil warehouse along with a transport chain; after an insulating time of ≥60 minutes, removing the coil from the insulating enclosure, and cooling it to room temperature in air, wherein the microalloying element Ti has a content of ≥0.03 wt %; the coiling is performed at a temperature of 500-700° C.

2. The production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel according to claim 1 , wherein the microalloying element Ti has a content of 0.03-0.10 wt %.

3. The production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel according to claim 1 , wherein the ingot is heated at a temperature of ≥1200° C., and a soaking time is ≥60 minutes.

4. The production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel according to claim 1 , wherein the ingot is heated at a temperature of 1200-1300° C., and the soaking time is 1-2 hours.

5. The production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel according to claim 1 , wherein the rough rolling is performed at a temperature of 1000-1200° C., wherein 3-8 passes of reciprocating rolling are performed, and a cumulative deformation is ≥50%.

6. The production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel according to claim 1 , wherein the finish rolling is performed with 6-7 passes of continuous rolling, wherein a cumulative deformation is ≥80%, and a final rolling temperature is 800-900° C.

7. The production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel according to claim 1 , wherein each hot-rolled coil is individually covered with an insulating enclosure within 20 minutes after it is unloaded.

8. The production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel according to claim 1 , wherein the hot-rolled coil is cooled at a cooling rate of ≤15° C./hour in the insulating enclosure.

9. The production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel according to claim 1 , wherein the insulating time of the hot-rolled coil is 1-5 hours.

Assignees

• Baosteel Zhanjiang Iron & Steel Co Ltd
• Baoshan Iron & Steel
• Baosteel Zhanjian Iron & Steel Co Ltd

Inventors

• Gao Xingjian
• Xu Jiachun
• Wang Ye

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• C21D1/84 Primary

  Controlled slow cooling (cooling-beds for metal rolling B21B43/00) · CPC title

• C22C38/14

  containing titanium or zirconium · CPC title

• B21B45/008

  Heat shields · CPC title

• C21D9/0068 Primary

  for particular articles not mentioned below · CPC title