Non-Oriented Electrical Steel Composition for Low Motor Vibration
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Solution Overview
Problem
Existing non-oriented electrical steel sheets face challenges in balancing magnetostriction and motor core iron loss properties, leading to increased noise and vibration in electrical motors, particularly due to the anisotropy of magnetostriction in the rolling plane.
Innovation Solution
A non-oriented electrical steel sheet with specific chemical composition and manufacturing process, including controlled application of alternating-current magnetic fields during rolling, reduces the in-plane average value of magnetostriction, thereby minimizing noise and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the magnetostriction constant λ100 is reduced by adjusting steel components, then the magnetostriction property is improved, but the iron loss property deteriorates
Solution Approach 1:
The invention changes the chemical composition parameters by strictly controlling the content of harmful elements (C≤0.0050%, P≤0.20%, S≤0.0050%, Al≤2.0%) and optimizing beneficial elements (Si: 2.0-5.0%, Mn: 2.0%). This parameter optimization simultaneously reduces magnetostriction constant while maintaining low iron loss, resolving the contradiction between magnetostriction property and iron loss property.
2Object-generated harmful factors
If the magnetostriction constant λ100 is reduced, then the magnetostriction property is improved, but the noise and vibration of the motor core do not necessarily decrease
Solution Approach 1:
The invention addresses the anisotropy of magnetostriction by optimizing the local chemical composition and microstructure of the electrical steel sheet. By controlling the distribution and content of alloying elements locally, the invention reduces magnetostriction in critical directions (especially λ100 and λ111) more effectively, which directly reduces the noise and vibration generated during motor operation.
Solution Approach 2:
The invention creates a composite microstructure through controlled alloying with multiple elements (Si, Mn, Ti, Nb, V) in specific proportions. This composite material approach at the microstructural level achieves reduced magnetostriction anisotropy while maintaining good magnetic properties, thereby effectively reducing motor noise and vibration.
3Object-generated harmful factors
If Si and Al content is adjusted to reduce magnetostriction, then the magnetostriction property is improved, but the balance between magnetostriction and iron loss properties becomes difficult to reconcile
Solution Approach 1:
The invention optimizes the parameters of multiple alloying elements simultaneously rather than adjusting only Si and Al. By setting Si at 2.0-5.0% and Mn at 2.0%, while strictly limiting C≤0.0050%, P≤0.20%, S≤0.0050%, and Al≤2.0%, the invention achieves a balanced composition that simultaneously improves magnetostriction properties and maintains low iron loss, resolving the difficulty in reconciling these two properties.
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 a low-noise, low-vibration electrical motor by reducing the in-plane average value of magnetostriction, enhancing the magnetic properties and reducing iron loss.
Implementation Method 1
magnetostriction of a non-oriented electrical steel sheet used as an iron core material of a motor is also known to cause noise and vibration of a motor
Implementation Method 2
reducing an in-plane average value of magnetostrictions in directions perpendicular to the respective magnetic field directions and parallel to the rolling plane resulting from applying an alternating-current magnetic field
Data Source
Figure 1~2
Figure 3
AI summary
A non-oriented electrical steel sheet that is effective in reducing the noise and vibration of electrical motors and that has a chemical composition containing, in mass%, C: 0.0050% or less, Si: 2.0 to 5.0%, Mn: 2.0% or less, P: 0.20% or less, S: 0.0050% or less, Al: 2.0% or less, N: 0.0050% or less, Ti: 0.0030% or less, Nb: 0.0010% or less, V: 0.0050% or less, and O: 0.0050% or less, wherein when an alternating-current magnetic field is applied so as to achieve a frequency of 50 Hz and a maximum magnetic flux density Bm of 1.5 T in a rolling direction (RD), a sheet width direction (TD), and a direction (DD) forming an angle of 45° with the rolling direction, in a rolling plane of the steel sheet , and zero-peak values of resulting magnetostrictions in directions perpendicular to the respective magnetic field directions and parallel to the rolling plane are represented as λ⊥HRD, λ⊥HTD, and λ⊥HDD, respectively, the absolute value of a magnetostriction in-plane average value λ⊥Have is 5×10-6 or smaller.