Non-oriented electrical steel sheet and manufacturing method therefor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing non-oriented electrical steel sheets face challenges in achieving high-frequency low iron loss and magnetic flux density due to the presence of fine impurities such as inclusions and precipitates, which hinder domain wall movement, while also suffering from reduced productivity due to lengthy secondary refining processes.
Innovation Solution
The steel sheet composition includes specific ranges of Si, Al, Mn, Zn, and trace elements like Y to control inclusion size and precipitate formation, optimizing magnetic properties without extensive secondary refining, through controlled heating, rolling, and annealing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large amount of specific resistance elements such as Si, Al, and Mn are added to obtain high-frequency low iron loss properties, then magnetic properties are improved, but productivity is reduced due to lengthy secondary refining processes
Solution Approach 1:
The patent optimizes the composition parameters by limiting Si to 2-6% and Al to 3% or less, which balances magnetic property improvement with reduced refining time requirements. This parameter optimization allows achieving low iron loss without requiring excessively long secondary refining processes
Solution Approach 2:
The patent controls inclusions and fine precipitates during the primary steelmaking process rather than relying solely on extended secondary refining. By preliminary controlling the composition and inclusion formation during steelmaking, the need for lengthy secondary refining is reduced while still achieving the required purity level
2Reliability
If impurity elements such as C, S, N, Ti, Nb, V are purified to an extremely low level to control inclusions and fine precipitates, then magnetic properties are improved, but productivity is dropped since secondary refining takes a long time
Solution Approach 1:
The patent sets specific compositional parameters (Si: 2-6%, Al: 3% or less) that enable achieving the required impurity control level without requiring excessively long secondary refining times. This optimized composition reduces the time needed for secondary refining while still controlling inclusions and precipitates effectively
Solution Approach 2:
The patent converts the potential harm of inclusions and fine precipitates into a benefit by controlling their composition and size through optimized alloying. By adding controlled amounts of Si and Al, the patent promotes the formation of larger, less harmful inclusions while reducing the need for extended refining time
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 solution results in improved magnetic properties and productivity, enabling high-frequency low iron loss and enhanced magnetic flux density, suitable for high-speed rotation applications like eco-friendly automobile motors and high-efficiency home appliances.
Implementation Method 1
improves the purity of the molten steel by comprising Zn in a specific range, so that inclusions and precipitates are coarsened
Implementation Method 2
through controlled heating, rolling, and annealing processes
Data Source
AI summary
A non-oriented electrical steel sheet according to an embodiment of the present invention comprises Si: 2.0 to 3.5 %, Al: 0.3 to 3.5 %, Mn: 0.2 to 4.5 %, Zn: 0.0005 to 0.02 % in wt% and Fe and inevitable impurities as a balance amount.