鋼の熱膨張計算機
金属部品が温度によって伸縮する量を計算します。長さ、温度変化、材料を入力すると、長さの変化量、最終的な長さ、1メートルあたりの伸びが得られます。
熱膨張
線膨張、ΔL = α L ΔT。係数は室温付近の平均値であり、高温ではわずかに上昇します。
線熱膨張係数
| 材料 | α (×10⁻⁶/°C) | α (×10⁻⁶/°F) | 10 m、ΔT 50 °Cでの膨張 |
|---|---|---|---|
| 炭素鋼 | 12.0 | 6.7 | 6.0 mm |
| ステンレス304 | 17.3 | 9.6 | 8.7 mm |
| ステンレス316 | 16.0 | 8.9 | 8.0 mm |
| ステンレス430 | 10.4 | 5.8 | 5.2 mm |
| 工具鋼 | 11.5 | 6.4 | 5.8 mm |
| 鋳鉄 | 10.5 | 5.8 | 5.2 mm |
| アルミニウム | 23.1 | 12.8 | 11.6 mm |
| 銅 | 16.5 | 9.2 | 8.2 mm |
| 真鍮 | 19.0 | 10.6 | 9.5 mm |
| チタン | 8.6 | 4.8 | 4.3 mm |
| ニッケル合金 | 13.0 | 7.2 | 6.5 mm |
| Invar 36 | 1.2 | 0.7 | 0.6 mm |
| コンクリート | 12.0 | 6.7 | 6.0 mm |
| ガラス | 9.0 | 5.0 | 4.5 mm |
よくある質問
鋼材の熱膨張はどのように計算しますか？
熱膨張係数に元の長さと温度変化を掛けます：ΔL = α × L × ΔT。炭素鋼の場合、αは約12×10⁻⁶ /°Cです。
鋼材の熱膨張係数はいくつですか？
炭素鋼は約12×10⁻⁶ /°Cです。ステンレス304は17.3とかなり高く、フェライト系430は10.4、Invar 36はわずか1.2です。そのため、寸法安定性が重要な用途ではInvarが使用されます。
鋼製梁はどれくらい膨張しますか？
10 mの炭素鋼梁を40 °C加熱すると、約4.8 mm膨張します。そのため、長い構造物や配管には伸縮継手や長穴が使用されます。
温度単位は重要ですか？
度の大きさのみが重要です。1 °Cの変化は1.8 °Fの変化に等しいため、°Fあたりの係数は°Cあたりの値を1.8で割った値になります。オフセットのある絶対温度ではなく、常に温度差を使用してください。
Thermal Expansion Calculator for Steel
Calculate the dimensional changes in steel components due to temperature variations. Understand and plan for thermal expansion or contraction in engineering and construction projects.
Thermal Expansion Results
Thermal Expansion Visualization
Understanding Thermal Expansion in Steel
What is Thermal Expansion?
Thermal expansion is the tendency of matter to change its dimensions in response to a change in temperature. Most materials expand when heated and contract when cooled. The change in length, area, or volume is proportional to the original dimension and the temperature change.
For engineering applications involving steel, accounting for thermal expansion is crucial in:
- Bridge design and expansion joints
- Railway track installation
- Piping systems and steam lines
- Building facades and structural elements
- Precision machine components
- Industrial equipment subject to temperature variations
How Thermal Expansion is Calculated
The basic formulas for calculating thermal expansion are:
Linear expansion: ΔL = α × L₀ × ΔT
Area expansion: ΔA = 2α × A₀ × ΔT
Volume expansion: ΔV = 3α × V₀ × ΔT
Where:
ΔL, ΔA, ΔV = Change in length, area, or volume
α = Coefficient of linear thermal expansion
L₀, A₀, V₀ = Initial length, area, or volume
ΔT = Temperature change
The coefficient of thermal expansion (α) varies between different types of steel based on their composition and structure.
Thermal Expansion Coefficients for Steel
The thermal expansion coefficient describes how much a material expands per unit length for each degree of temperature increase.
| Steel Type | Coefficient (α) in 10⁻⁶/°C | Temperature Range |
|---|---|---|
| Carbon Steel | 11.7 | 20-100°C |
| Mild Steel | 13.0 | 20-100°C |
| Stainless Steel 304 | 10.8 | 20-100°C |
| Stainless Steel 316 | 16.0 | 20-100°C |
| Structural Steel | 14.0 | 20-100°C |
| Tool Steel | 12.0 | 20-100°C |
| Low Expansion Steel | 10.0 | 20-100°C |
Note: These values may vary slightly depending on the exact composition and production method of the steel.
Practical Considerations for Engineers
- Expansion Joints: For long steel structures, expansion joints should be provided at appropriate intervals to accommodate thermal movement.
- Fixing Points: Consider where the structure is fixed and where it's free to move to predict the direction of expansion.
- Thermal Stress: If a component is constrained and cannot expand freely, thermal stress will develop according to: σ = E × α × ΔT (where E is Young's modulus).
- Differential Expansion: When different materials are joined, their different expansion rates can cause bending or warping.
- Temperature Range: Design for the full range of temperatures the structure will experience, not just average conditions.
Using This Calculator
- Select the object type (linear, area, or volume)
- Enter the initial dimensions
- Specify the initial and final temperatures
- Choose the steel type or enter a custom thermal expansion coefficient
- Indicate if the element has movement constraints
- Click "Calculate Thermal Change" to see results
The calculator will display the expected dimensional changes and, if requested, detailed analysis including thermal stress calculations for constrained elements.