Continuous Annealing Line With Induction Heating for Phase Fraction Control
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Solution Overview
Problem
Conventional continuous annealing furnaces face challenges in quickly adjusting to temperature changes and controlling the phase fraction of steel sheets, leading to variations in mechanical properties and reduced productivity due to thermal inertia and low controllability.
Innovation Solution
A continuous annealing line equipped with an induction heating device between the soaking and cooling zones, controlled by a phase fraction prediction model using machine learning, allows for rapid adjustment of annealing conditions based on predicted phase fraction variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If radiant tube burners are used to heat steel sheets, then the steel sheets are heated uniformly, but the thermal inertia is large and the temperature adjustment response is slow
Solution Approach 1:
The heating furnace is divided into multiple independent heating zones, each equipped with its own radiant tube burners. This segmentation allows independent temperature control in each zone, enabling faster and more flexible temperature adjustments without affecting the entire furnace, thereby reducing the effective thermal inertia of the system.
Solution Approach 2:
The system implements dynamic temperature control by adjusting the burner output and steel sheet conveyance speed in real-time based on process requirements. The conveyance speed can be varied to control residence time in each heating zone, allowing the system to adapt quickly to different temperature settings and reduce thermal inertia effects.
2Stability of the object's composition
If the furnace length is increased to allow sufficient soaking time for microstructure control, then the microstructure is properly controlled, but the thermal inertia increases and temperature adjustment becomes slower
Solution Approach 1:
The soaking process is divided into multiple heating zones with different temperature profiles. Each zone contributes to the overall microstructure control, allowing the required soaking time to be achieved without needing a single excessively long furnace. The segmented approach enables faster temperature adjustments between zones.
Solution Approach 2:
The system dynamically adjusts the conveyance speed of steel sheets through different heating zones to optimize residence time. By varying speeds in different zones, the system achieves proper microstructure control while maintaining flexibility for quick temperature changes, reducing the effective soaking time required for temperature adjustments.
3Manufacturing precision
If the conveyance speed is reduced to allow proper annealing, then the annealing quality is improved, but the productivity decreases
Solution Approach 1:
The annealing process is divided into multiple heating zones, each optimized for specific annealing requirements. This allows different sections of the steel sheet to receive appropriate heat treatment simultaneously, maintaining high annealing quality while increasing overall production speed through parallel processing.
Solution Approach 2:
The conveyance speed is dynamically adjusted in different heating zones rather than maintaining a uniform slow speed throughout. This enables proper annealing in critical zones while moving steel sheets faster through less critical zones, thereby improving overall productivity without sacrificing annealing quality.
4Speed
If the furnace temperature is increased to accelerate heating, then the heating speed increases, but the temperature distribution becomes uneven and thermal inertia increases
Solution Approach 1:
The heating furnace is divided into multiple zones with independent temperature control. Each zone can be heated at optimal rates without overwhelming the entire system, allowing fast heating while maintaining temperature uniformity through distributed control of thermal input across segments.
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
This approach enables precise control of steel sheet phase fraction, ensuring consistent mechanical properties and improved productivity by rapidly adjusting annealing conditions.
Implementation Method 1
at least one induction heating device disposed between the soaking zone and the cooling zone
Implementation Method 2
Radiant tube burners are typically used as heaters in annealing furnaces, which use gas combustion to heat metal tubes (radiant tubes) and indirectly heat steel sheets with the radiant heat
Implementation Method 3
PTL 2 describes a technology for determining the phase fraction of a steel sheet from changes in magnetic properties
Data Source
AI summary
Provided are a continuous annealing line, a continuous annealing method, a method of producing a cold-rolled steel sheet, and a method of producing a coated or plated steel sheet that precisely predict a phase fraction of a steel sheet under a high temperature condition and rapidly adjust an annealing condition to reflect a predicted phase fraction variation. The continuous annealing line is for a steel sheet and includes a heating zone (6), a soaking zone (7), and a cooling zone (8), in this order, at least one induction heating device (9) disposed between the soaking zone (7) and the cooling zone (8), and a control device that sets operating conditions of the induction heating device based on a phase fraction during annealing obtained by a phase fraction prediction model.