SAPH440 Structural Steel: プロパティのガイド, 用途 & 製造

If you’re working on automotive frames, light structural projects, or machinery parts that need a mix of形成性, 強さ, そして溶接性 - SAPH440 structural steel あなたの一番の選択です. Designed specifically for automotive and general structural use (per JIS standards), this low-carbon steel balances durability with easy shaping, making it a favorite for manufacturers worldwide. このガイドは、選択に必要なすべてを分類します, 使用, and maximize SAPH440 for your projects.

1. Material Properties of SAPH440 Structural Steel

SAPH440’s performance comes from its carefully calibrated化学組成—low carbon for workability, plus controlled manganese for strength. Let’s explore its key traits in detail.

化学組成

SAPH440 is a low-carbon, non-alloy steel optimized for forming and welding. Here’s its exact composition (per JIS G 3113 基準):

物理的特性

These traits make SAPH440 easy to integrate into manufacturing (especially automotive):

• 密度: 7.85 g/cm³ (same as most structural steels—simplifies weight calculations for vehicle frames or beams)
• 融点: 1425–1538°C (compatible with standard welding, ローリング, and stamping processes)
• 熱伝導率: 51.9 w/(M・k) (spreads heat evenly—reduces warping when welding thin automotive parts)
• 熱膨張係数: 12.0 µm/(M・k) (low enough to handle temperature changes in vehicle engines or outdoor structures)
• 電気抵抗率: 1.67 µΩ・m (not used for electrical components, but useful for safety planning in industrial settings)

機械的特性

SAPH440’s mechanical strength is tailored for medium-stress applications like automotive frames. Here are its key performance metrics:

• 抗張力: 440–570 MPa (handles moderate pulling forces—ideal for vehicle chassis or structural beams)
• 降伏強度: 270–410 MPa (maintains shape under load—critical for suspension components or building columns)
• 硬度: 140–180 HB (soft enough to form into complex shapes, but tough enough to resist minor wear)
• 衝撃の靭性: 高い (absorbs small impacts without breaking—great for automotive bumpers or agricultural machinery)
• 延性: 高い (曲がることができます, 刻印, or rolled into tight shapes—e.g., curved vehicle frames or thin pipeline sections)
• 伸長: 17–22％ (stretches significantly before breaking—avoids sudden failure in crash scenarios or structural stress)
• 疲労抵抗: 適度 (works for parts with regular stress, like vehicle suspension arms, but not constant vibration)
• 骨折の靭性: 高い (prevents catastrophic breaks—safe for safety-critical parts like automotive chassis)

その他の重要なプロパティ

• 良い溶接性: Joins easily with MIG, ティグ, or spot welding—no preheating needed for sheets up to 10 厚さmm (saves time in automotive assembly lines).
• 優れた形成性: Excels at cold stamping and hot rolling (can be shaped into thin, complex parts like vehicle door frames or structural brackets).
• 中程度の腐食抵抗: Resists rust in dry indoor environments—needs coating (like galvanizing or automotive paint) for outdoor or wet use (例えば。, marine parts or pipelines).
• タフネス: Performs reliably in temperatures from -5°C to 50°C (suitable for most climates, including cool temperate regions).

2. Applications of SAPH440 Structural Steel

SAPH440’s blend of formability and strength makes it a staple in industries where shaping flexibility and durability matter—especially automotive. 現実世界の問題を解決する方法は次のとおりです:

自動車

SAPH440 is most widely used in automotive manufacturing for key structural parts:

• 車両フレーム: Main chassis for sedans, hatchbacks, or small SUVs—its 形成性 allows for lightweight, aerodynamic designs, そしてその 強さ protects passengers in minor crashes.
• サスペンションコンポーネント: Control arms and wishbones—handles road vibrations and load without bending.
• シャーシパーツ: フロアパン, ドアフレーム, and bumper supports—easy to stamp into precise shapes for mass production.
• ケーススタディ: An automotive manufacturer used SAPH440 for a compact car’s chassis. スチール 延性 enabled a 10% weight reduction vs. older carbon steels, 燃料効率の向上 5%. 後 3 years of testing, the chassis showed no fatigue cracks, even in rough road conditions.

工事

建設中, SAPH440 is used for light-to-medium structural parts:

• 構造鋼コンポーネント: Non-load-bearing frames for small commercial buildings or residential extensions.
• ビーム そして 列: For lightweight structures like garden sheds, カーポート, or 1–2 story homes (not high-rises).
• 橋: Small pedestrian bridges or bike paths—its 溶接性 オンサイトアセンブリを簡素化します.
• 例: A construction firm used SAPH440 beams for a 150-meter pedestrian bridge. スチール 形成性 allowed curved sections for aesthetics, そしてその 強さ supported 500 kg/m² loads. With a paint coat, the bridge lasted 8 錆のない年.

機械工学

Mechanical engineers rely on SAPH440 for small-to-medium components:

• ギア: Small gears for household appliances or light machinery—its 加工性 allows precise tooth shaping.
• シャフト: Light machine shafts (例えば。, for conveyor belts or small motors)—handles low-to-moderate rotational stress.
• 機械部品: ブラケット, ハウジング, およびファスナー (cost-effective for high-volume production of shaped parts).

パイプライン業界

SAPH440 works for low-to-medium pressure, small-diameter pipelines:

• Ideal for residential water lines or low-pressure air pipelines (not high-pressure oil/gas). その 延性 lets it be bent around obstacles, そしてその 中程度の腐食抵抗 (エポキシコーティング付き) protects against soil moisture.

海洋産業

For mild marine uses (沿岸地域, not open ocean):

• 船の構造: Interior parts like cabin frames or storage locker supports (not hulls—those need corrosion-resistant steel).
• オフショアプラットフォーム: Temporary handrails or non-critical components (with galvanizing to resist salt spray).

農業機械

Farmers use SAPH440 for lightweight, 耐久性のある部分:

• Tractor parts: Hoods, フェンダー, and tool mounts—easy to form into protective shapes, and tough enough to handle field debris.
• プラウ そして ハロー: フレームコンポーネント (not cutting edges)—resists wear from soil and minor impacts.

3. Manufacturing Techniques for SAPH440 Structural Steel

SAPH440 is designed for mass production—its properties work seamlessly with standard steel manufacturing processes. これが段階的な内訳です:

スチール製造プロセス

Two main methods produce SAPH440, depending on volume:

1. 基本的な酸素炉 (bof): 大きなバッチに使用されます (例えば。, シート, コイル, またはバー). Molten iron is mixed with manganese and silicon, then oxygen is blown in to adjust carbon to 0.12–0.18%. Fast and cost-effective for automotive-grade steel coils.
2. 電気弧炉 (EAF): Ideal for small batches or custom parts (例えば。, 特殊なブラケット). スクラップスチールは溶けています, and elements (Mn, そして) are added to meet SAPH440 specs. Flexible for low-volume projects.

熱処理

SAPH440 rarely needs complex heat treatment, but these processes enhance its properties:

• 正規化: 850〜900°Cに加熱します, 空気を冷やします. Softens the steel after rolling (makes it easier to stamp into automotive parts).
• アニーリング: 800〜850°Cに加熱します, ゆっくりと冷却します. Makes the steel extra ductile for intricate shapes (例えば。, curved vehicle frames).
• クエンチングと焼き戻し: Rarely used—only for parts needing extra hardness (例えば。, 頑丈なギア).

プロセスの形成

SAPH440 excels in forming, especially for thin sheets:

• ホットローリング: Heats to 1100–1200°C, rolls into coils or sheets (main method for automotive-grade steel).
• コールドローリング: Rolls at room temperature. Creates smooth, 薄いシート (used for stamping door frames or floor pans).
• 鍛造: Used for thick parts (例えば。, サスペンションコントロールアーム)—heats steel and hammers it into shape to boost strength.
• 押し出し: 中空の部分を作るためにダイを通して加熱鋼を押します (例えば。, small pipeline sections or gear housings).
• スタンピング: The most common process for SAPH440—high-pressure presses cut or bend steel into automotive parts (例えば。, bumper supports or chassis components) at high speeds.

表面処理

耐久性と耐食性を高めるため:

• 亜鉛メッキ: 溶融亜鉛に浸る. Ideal for outdoor parts (例えば。, agricultural machinery or bridge beams)—lasts 15+ 錆のない年.
• 絵画: Applies automotive-grade enamel or epoxy paint. Used for vehicle frames or indoor machine parts to prevent rust.
• ショットブラスト: Blasts with tiny metal balls to remove dirt, 規模, or rust. Prepares surfaces for welding or coating.
• コーティング: Uses fusion-bonded epoxy for pipelines (prevents corrosion in water lines) or zinc-nickel coating for automotive parts (resists saltwater damage from road de-icing).

4. SAPH440 Structural Steel vs. その他の材料

How does SAPH440 compare to other common steels and alloys? あなたが選ぶのを助けるためにそれを分解しましょう:

SAPH440 vs. 炭素鋼 (例えば。, sae 1005)

SAPH440 vs. 高強度の低合金 (HSLA) 鋼 (例えば。, X60)

• 化学組成: HSLA has alloys (Mn, で) 超高強度のために; SAPH440 is plain carbon (no alloys).
• プロパティ: HSLAはです 30% stronger but harder to form; SAPH440 is more workable but not for extreme stress.
• アプリケーション: HSLA = high-pressure pipelines, skyscraper beams; SAPH440 = automotive frames, light structures.

SAPH440 vs. ステンレス鋼 (例えば。, 304)

SAPH440 vs. アルミニウム合金 (例えば。, 6061)

• 重さ: アルミニウムはです 1/3 ライター, but SAPH440 is 20% より安く、溶接が簡単です.
• 強さ: SAPH440 has higher tensile strength (440–570 MPA対. aluminum’s 310 MPA).
• アプリケーション: Aluminum = lightweight parts (航空機コンポーネント); SAPH440 = cost-effective structural parts (自動車フレーム).

5. Yigu Technology’s Perspective on SAPH440 Structural Steel

Yiguテクノロジーで, we see SAPH440 as a “automotive-focused workhorse” for clients needing formability and strength. そのexcellent stamping and welding traits make it perfect for automotive mass production, cutting assembly time and costs. We often recommend it to car manufacturers and small construction firms—its low cost and consistent properties reduce project risks. 屋外で使用します, we pair it with galvanizing or epoxy coating to boost corrosion resistance. SAPH440 isn’t for extreme stress, but for most light-to-medium structural needs, it’s the most cost-effective choice.

FAQ About SAPH440 Structural Steel

1. Can SAPH440 be used for high-pressure oil pipelines?

No—SAPH440’s yield strength (270–410 MPa) is too low for high-pressure oil/gas (必要なもの 480+ MPa for X60 steel). Use it only for low-to-medium pressure lines, like residential water or natural gas.

2. Is SAPH440 suitable for cold climates (below -5°C)?

It’s not ideal—its impact toughness drops below -5°C, increasing brittle failure risk. For cold regions (例えば。, northern Europe or Canada), use alloy steels with nickel (like SAE 4340) or HSLA steels designed for low temperatures.

3. Can SAPH440 be welded to aluminum parts?

はい, but it needs specialized techniques (like friction stir welding or brazing) because steel and aluminum have different melting points. We recommend using a transition material (例えば。, aluminum-steel clad plates) to ensure a strong bond—avoid direct arc welding, which causes weak, brittle joints.