Duplex stainless steel cold rolling annealing and pickling process

A technology for cold rolling, annealing, pickling, and duplex stainless steel. It is used in manufacturing tools, furnace types, and furnaces. , stabilize the annealing temperature, and improve the effect of pickling efficiency

Active Publication Date: 2016-05-18
GANSU JIU STEEL GRP HONGXING IRON & STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a duplex stainless steel cold-rolled annealing and pickling process to solve the problems of poor surface pickling, widening and thickness reduction of duplex stainless steel in the cold-rolling annealing and pickling process, and to ensure that the product Surface quality and dimensional stability, less pickling times and lower production costs

Method used

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  • Duplex stainless steel cold rolling annealing and pickling process
  • Duplex stainless steel cold rolling annealing and pickling process
  • Duplex stainless steel cold rolling annealing and pickling process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] A cold-rolled hard state 2205 duplex stainless steel annealing and pickling process with a thickness of 1.0mm comprises the following steps:

[0026] a. Connect 304 austenitic stainless steel coils to the front and rear ends of the duplex stainless steel coils;

[0027] b. Set the process speed as 30m / min, get the TV value as 30, set the temperature of each annealing furnace zone according to the TV value according to the annealing curve as shown in Table 2 below:

[0028] Table 2 Furnace temperature in each zone during annealing of duplex stainless steel with TV value of 30 (°C)

[0029]

[0030] c. The annealed stainless steel coil is subjected to Na 2 SO 4 Electrolysis, Na 2 SO 4 Solution specific gravity 1.15g / cm 3 , temperature 70°C, pH value 5, electrolysis current 100A / cm 2 , electrolysis speed 20m / min;

[0031] d. Continue to HNO the duplex stainless steel coil in c 3 Electrolysis, HNO 3 The concentration is 130g / L, the temperature is 60°C, and the...

Embodiment 2

[0037] A cold-rolled hard state 2205 duplex stainless steel annealing and pickling process with a thickness of 0.5mm comprises the following steps:

[0038] a. Connect 309S austenitic stainless steel coils to the front and rear ends of the duplex stainless steel coils;

[0039] b. Set the process speed as 40m / min, get the TV value as 20, and set the temperature of each zone according to the TV value as shown in Table 3 below:

[0040] Table 3 Furnace temperature in each zone during annealing of duplex stainless steel with TV value of 20 (°C)

[0041]

[0042] c. The annealed stainless steel coil is subjected to Na 2 SO 4 Electrolysis, Na 2 SO 4 Solution specific gravity 1.15g / cm 3 , temperature 65°C, pH value 3, electrolysis current 120A / cm 2 , electrolysis speed 10m / min;

[0043] d. Continue to HNO the duplex stainless steel coil in c 3 Electrolysis, HNO 3 The solution concentration is 110g / L, the temperature is 55°C, and the electrolysis current is 120A / cm 2 ,...

Embodiment 3

[0049] The annealing and pickling of this embodiment is that the cold-rolled hard state 2205 duplex stainless steel coil with a thickness of 1.5mm comprises the following steps:

[0050] a. Connect 310S austenitic stainless steel coils to the front and rear ends of the duplex stainless steel coils;

[0051] b. Set the process speed as 40m / min, get the TV value as 60, and set the temperature of each zone according to the TV value as shown in Table 4 below:

[0052] Table 4 Furnace temperature in each zone during annealing of duplex stainless steel with TV value of 60 (°C)

[0053]

[0054] c. The annealed stainless steel coil is subjected to Na 2 SO 4 Electrolysis, Na 2 SO 4 Solution specific gravity 1.15g / cm 3 , temperature 75°C, pH value 4, electrolysis current 200A / cm 2 , electrolysis speed 30m / min;

[0055] d. Continue to HNO the duplex stainless steel coil in c 3 Electrolysis, HNO 3 The solution concentration is 150g / L, the temperature is 60°C, and the electr...

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Abstract

The invention discloses a duplex stainless steel cold rolling annealing and pickling process and belongs to the technical field of duplex stainless steel smelting. The process comprises the following steps: respectively connecting stainless steel rolls with annealing temperature approximating to the annealing temperature of duplex stainless steel to the front end and the rear end of the duplex stainless steel; setting process speed, calculating TV value according to the thickness and the process speed of the steel rolls, setting the hearth temperature of each region according to the TV value and carrying out annealing on the steel rolls; and then carrying out Na2SO4 electrolysis, HNO3 electrolysis, scrubbing, pickling with mixed acid and washing with desalted water on the stainless steel rolls after annealing, and finally cutting off the stainless steel rolls at the front end and the rear end of the duplex stainless steel roll, thus obtaining the duplex stainless steel roll finished products. According to the invention, by using proper annealing and pickling processes, the problems that black strips appear on the rear surface of the duplex stainless steel after pickling and width shrinking and thickness reduction are easy to cause are solved, an oxidation film on the surface of the duplex stainless steel is completely removed, the surface glossiness of the steel rolls is high, and the quality requirements of products can be met.

Description

technical field [0001] The invention belongs to the technical field of duplex stainless steel smelting, and in particular relates to a duplex stainless steel cold-rolled annealing and pickling process. Background technique [0002] Duplex stainless steel refers to stainless steel in which ferrite and austenite each account for about 50%, and generally the content of less phases needs to reach at least 30%. In the case of low C content, the Cr content is 18-28%, and the Ni content is 3-10%. Its scale structure is complex, and annealing and pickling during cold rolling are the key links that affect product performance and surface quality. Among them, whether the pickling process is reasonable or not directly affects the surface quality of the product, and restricts the production progress to a certain extent; and the annealing temperature has an important impact on the mechanical properties of duplex stainless steel. With the increase of annealing temperature, the duplex The...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23F17/00C21D1/26C21D9/52C25F1/06C23G1/08
CPCC21D1/26C21D9/525C23F17/00C23G1/086C25F1/06
Inventor 陈兴润申德惠恺潘吉祥
Owner GANSU JIU STEEL GRP HONGXING IRON & STEEL CO LTD
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