Ultra-Thin Hot-Rolled Strip Production With Low Scale Formation
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Solution Overview
Problem
Current methods for producing hot-rolled steel strips cannot achieve thicknesses below 0.6 mm while maintaining a high temperature for austenitic rolling and minimizing scale formation, making it necessary to undergo pickling before corrosion coating.
Innovation Solution
A continuous production process that includes initial thermal conditioning and descaling with an induction edge heater and water descaler, followed by controlled roughing and finishing rolling with additional induction furnaces in a protective atmosphere, and mechanical scale-breaking devices to produce ultra-thin strips with minimal scale for direct corrosion coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the steel strip is rolled at high temperature to maintain austenitic structure for ultra-thin sections, then the strip thickness can be reduced below 0.6 mm, but scale formation increases significantly requiring pickling
Solution Approach 1:
The patent applies preliminary descaling action by introducing a water descaler between the roughing mill and finishing mill. This removes scale formed during roughing before the material enters the finishing mill, preventing further scale formation during the critical finishing process and enabling ultra-thin section production without excessive scale buildup
Solution Approach 2:
The patent creates a protective atmosphere environment in the finishing mill by introducing inert gas (nitrogen) to displace oxygen. This inert atmosphere prevents oxidation of the steel strip surface during finishing rolling, thereby minimizing scale formation while maintaining the high temperature austenitic rolling process necessary for ultra-thin sections
2Temperature
If induction heating is used to heat the transfer bar before finishing rolling, then the austenitic temperature range is maintained for better rolling control, but oxide formation increases on the strip surface
Solution Approach 1:
The patent applies preliminary descaling action by introducing a water descaler between the roughing mill and finishing mill. This removes scale formed during roughing before the material enters the finishing mill, preventing further scale formation during the critical finishing process and enabling ultra-thin section production without excessive scale buildup
Solution Approach 2:
The patent creates a protective atmosphere environment in the finishing mill by introducing inert gas (nitrogen) to displace oxygen. This inert atmosphere prevents oxidation of the steel strip surface during finishing rolling, thereby minimizing scale formation while maintaining the high temperature austenitic rolling process necessary for ultra-thin sections
3Manufacturing precision
If multiple processing stages are used to produce ultra-thin strips, then the strip quality is improved, but the plant complexity and production cost increase
Solution Approach 1:
The patent combines multiple functions into integrated processing stages. The water descaler and protective atmosphere system are integrated into the finishing mill workflow, allowing simultaneous descaling and protected rolling in a unified process flow rather than separate sequential operations, thereby reducing plant complexity while maintaining ultra-thin strip quality
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the production of hot-rolled steel strips down to 0.3 mm thickness with reduced production costs and energy consumption, minimizing scale formation and allowing direct corrosion coating without preliminary surface treatments.
Implementation Method 1
an induction edge heater
Implementation Method 2
an induction heater
Implementation Method 3
initial thermal conditioning and descaling section comprising in sequence, in the direction of slab advancement, an induction edge heater (4.1), an induction heater (4.2) and a water descaler (5)
Implementation Method 4
a second induction furnace, - a finishing mill comprising four stands
Data Source
Figure 1a
Figure 1b
Figure 1c
AI summary
Plant and process for the continuous production of hot-rolled steel strips with a minimum thickness of 0,3 mm, comprising a continuous casting device (1) of thin or medium slabs with a thickness between 40 and 150 mm and a maximum width of at least 2100 mm followed by a roughing mill (2), a first induction furnace, a water descaler, a second induction furnace, a finishing mill, a cooling station, a cutting station and a winding station, a system for feeding a protective atmosphere containing ≤3% vol. of oxygen being provided at least from the inlet of the second induction furnace to the third stand of the finishing mill, and further comprising, between the continuous casting device (1) and the roughing mill (2), an initial thermal conditioning and descaling section (4) comprising in sequence an induction edge heater (4.1), an induction heater (4.2) for the rest of the slab surface and a water descaler (5).