Casting-Rolling Layout for Ultra-Thin Strip Without Induction Heating
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Solution Overview
Problem
Existing casting-rolling systems face challenges in producing thin or ultra-thin steel strips below 1.2 mm, particularly in continuous operation, due to process control issues and the need for expensive and maintenance-intensive induction heating to maintain the required rolling temperature, which limits production efficiency and flexibility.
Innovation Solution
A casting-rolling system with adjustable casting molds and a configuration of at least seven roll stands, including optional parallel casting plants and continuous furnaces, that allows for the production of thin slabs with thicknesses of 90 to 150 mm, eliminating the need for induction heating and enabling flexible batch or continuous operation to produce a wide range of steel grades without intermediate reheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If induction heating is used to maintain rolling temperature for thin strips below 1.2 mm, then the required rolling temperature is maintained, but the system becomes expensive and maintenance-intensive
Solution Approach 1:
The patent removes the induction heating device from the rolling mill system. Instead of using expensive and maintenance-intensive induction heating, the system relies on the casting heat retained in the thin slab to maintain the required rolling temperature throughout the multi-stand rolling process, thereby eliminating complex heating equipment while still achieving the necessary temperature control for producing thin strips below 1.2 mm
2Manufacturing precision
If thin strips below 1.2 mm are introduced into the roll gap, then ultra-thin strip production is achieved, but process control difficulties and cobbling interruptions occur
Solution Approach 1:
The patent applies preliminary action by ensuring the thin slab maintains adequate temperature from the casting process itself before entering the rolling mill. The casting conditions are optimized to retain sufficient heat in the thin slab, so that when the strip is introduced into the roll gap at ultra-thin thicknesses, it already has the necessary thermal energy to prevent cobbling and ensure smooth, interruption-free rolling through all seven stands
3Manufacturing precision
If casting thickness is reduced to produce thinner final strips, then the final strip thickness is reduced, but the casting process becomes more challenging to control
Solution Approach 1:
The patent changes the key parameter of casting thickness to a specific range (90-150 mm) that is thick enough to retain adequate casting heat for subsequent rolling of ultra-thin strips, yet thin enough to achieve the desired final product thickness. This parameter optimization, combined with controlling casting speed and mold conditions, allows the system to produce final strips from 0.8 mm to 26 mm without requiring excessively thin casts that would be difficult to control
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
The system achieves cost-effective and reliable production of thin or ultra-thin steel strips from 0.8 mm to 25.4 mm, with an annual capacity of 4.0 to 5.0 million tons, by optimizing the casting and rolling process to maintain the required rolling temperature, ensuring efficient energy use and reduced maintenance costs.
Implementation Method 1
a continuous furnace (7a, 7b) arranged downstream of the casting plant, in order to heat and/or homogenize the temperature of the cast thin slab to the required rolling temperature
Implementation Method 2
at least one casting plant for casting a thin slab... In this case, cast thin slabs of different formats both in terms of thickness and width, usually with a thickness of up to 60 mm and a width of up to 2,000 mm, are cast in a continuous casting process
Data Source
AI summary
A method for producing an ultra-thin strip of less than 0.8 mm from cast steel in batch/continuous operation with a casting-rolling system. The method includes casting a thin slab having a casting thickness of 90-150 mm and width of at least 1000 mm at a casting speed of 7 m/min. The thin slab is heated/homogenized to a first temperature in a continuous furnace and subsequently rolled by at least seven final roll stands into an ultra-thin band. Neither the thin slab nor strip undergo inductive heating during production. The thin slab rolling steps include rough rolling the thin slab at the heated/homogenized first temperature by a roughing stand; heating/homogenizing the rough-rolled thin slab to a second temperature by a further continuous furnace; and finally rolling the rough-rolled thin slab at the second temperature to the ultra-thin strip by the final roll stands arranged downstream of the further continuous furnace.