Z akého materiálu sú žeriavové háky kované?

Žeriavové háky sú vo všeobecnosti kované z nízkouhlíkovej legovanej ocele alebo vysoko uhlíkovej legovanej ocele. The specific choice of material depends on the tonnage of the lifted load and the requirements of the working environment. For large-tonnage heavy objects, forged hooks are usually used because they have a larger load-bearing capacity and a higher safety factor.

The process of making a forged crane hook involves placing a preheated steel billet into a forging machine and impacting or extruding it into the preliminary shape of the žeriavový hák. During the forging process, teplota, force and speed need to be strictly controlled to ensure the strength and shape of the hook. Okrem toho, in order to eliminate cold stress, thermal stress and welding stress, the hook must also undergo appropriate heat treatment, such as tempering, during the manufacturing process.

Mainstream forged materials for crane hook

1. 42CrMo legovaná oceľ

   • Characteristics: vysoká pevnosť v ťahu (≥1000MPa), excellent toughness, hardness reaches HRC 45-50 po uhasení + temperovanie.

   • Aplikácia: Suitable for 5-ton to 50-ton standard hooks, widely used in construction, ports and other scenarios.

2. 34CrNiMo6 alloy steel

   • Vlastnosti: Ultra-high strength (tensile strength up to 1200MPa), outstanding fatigue resistance, suitable for heavy-load impact conditions.

   • Aplikácia: Heavy-duty hooks above 20 ton, such as wind power equipment installation and heavy machinery handling.

3. AISI 4140 (American Standard)

   • Characteristics: High hardenability, odolnosť proti opotrebovaniu, often used in harsh environments (such as high temperature or corrosive places).

   • Aplikácia: Mainstream materials in European and American markets, complying with ASME B30.10 standards.

Crane hook material selection

• Load requirements: Low alloy steel (such as 35CrMo) can be used for light loads (≤10 tons), and high-grade materials are required for heavy loads.
• Prispôsobivosť prostredia: High humidity and salt spray environments require surface galvanizing/Dacromet treatment; low temperature environments require -60°C impact toughness materials (such as S355J2 of EN 10025 štandardná).
• Bezpečnostná certifikácia: Must meet the material performance requirements of ISO 4309, GB/T 10051.1 and other standards.

Materials for special scenes

• Stainless steel hook: 304/316 nehrdzavejúca oceľ, used in clean or highly corrosive environments such as food and medicine (but the strength is lower than alloy steel).
• Titanium alloy hooks: ultra-lightweight, corrosion-resistant scenarios such as aerospace and marine engineering, which are extremely costly.

Forging process and inspection of crane hooks

• Process: die forging → heat treatment (kalenie a temperovanie) → mechanical processing → surface anti-corrosion treatment.
• Quality inspection: 100% magnetická kontrola častíc (detekcia trhlín) + ultrasonic inspection (internal defect inspection) + static load test (2 times rated load verification).