News

Causes : Overload, insufficient material yield strength (such as low-grade alloy steel), local high temperature (welding maintenance causes metallographic changes).

Characteristics : The opening of the hook is enlarged (it will be scrapped if it exceeds 15% of the original size) and the hook body is obviously bent.

reason :

• Alternating load action (frequent lifting close to the rated load);

• Stress concentration (the thread root and hook neck transition area are not rounded);

• Micro crack growth (material inclusions or corrosion pits as the origin).

Features : The fracture has shell-like texture, mostly occurring in the high stress area on the inner side of the hook body.

Causes : Low temperature environment (the toughness of carbon steel drops sharply below -20°C), hydrogen embrittlement (improper electroplating or pickling process), and internal defects of the material (pores, slag inclusions).

Features : The fracture is smooth without plastic deformation, often accompanied by sudden fracture.

reason :

• The friction of the wire rope causes the hook groove to wear (especially when lifting at a single point frequently);

• Pitting and stress corrosion cracking (Cl⁻ corrosion) in chemical/marine environments;

• Poor lubrication increases wear.

Material selection : DG20MnTiB and other low carbon alloy steels are preferred, with impact energy ≥ 27J at -40℃.

Structural optimization : T-section hook body (bending resistance increased by 30% compared with trapezoidal section), transition zone R angle ≥ 12mm.

Safety factor : According to FEM 1.001 standard, the rated load must meet ≥4 times the static load safety factor.

Load Control :

• Install an electronic limiter (such as a SICK load sensor) to automatically cut off power when overloaded;

• Non-standard operations such as oblique pulling and sudden braking are prohibited.

Regular testing :

• Magnetic particle testing (MT): Check surface cracks every 6 months (focus on hook neck threads);

• Ultrasonic Thickness Gauging (UT): monitor corrosion thinning areas (shortened to 3 months in chemical environments).

Scrap standards :

• Hook deformation > 10% of original size;

• Crack depth > 2mm or length > 10% of hook diameter.

Anti-corrosion treatment : hot-dip galvanizing (thickness ≥ 80μm) or spray polyurethane coating (salt spray test ＞1000h).

Lubrication solution : The hook neck bearing is lubricated with lithium-based grease (NLGI grade 2), and the wire rope contact surface is coated with graphite paste.

Intelligent monitoring :

• Strain gauge + wireless transmission to monitor stress distribution in real time;

• AI algorithm analyzes vibration spectrum and predicts fatigue life.

Low temperature conditions : Use austenitic stainless steel (such as 06Cr19Ni10) or perform a -50℃ Charpy impact test.

Corrosive environment : Use duplex steel 2205 or external cathodic protection (sacrificial anode method).

A port crane hook fracture accident :

• Cause of failure : fatigue crack at the root of the hook neck thread (the backing groove was not turned according to the standard) + long-term overload of 5%~10%.

• Improvement measures : Use a fully forged one-piece hook (to eliminate thread stress concentration) + install a wireless acoustic emission monitoring system.

Digital twin warning : Use ANSYS simulation to simulate stress cloud maps under different working conditions and predict high-risk areas.

Self-healing coating : Microencapsulated corrosion inhibitors are embedded in the coating and automatically released to repair after wear.

Blockchain traceability : records the entire life cycle data of the hook (smelting → forging → use) to ensure quality traceability.

Causes : Overload, insufficient material yield strength (such as low-grade alloy steel), local high temperature (welding maintenance causes metallographic changes).

Characteristics : The opening of the hook is enlarged (it will be scrapped if it exceeds 15% of the original size) and the hook body is obviously bent.

reason :

• Alternating load action (frequent lifting close to the rated load);

• Stress concentration (the thread root and hook neck transition area are not rounded);

• Micro crack growth (material inclusions or corrosion pits as the origin).

Features : The fracture has shell-like texture, mostly occurring in the high stress area on the inner side of the hook body.

Causes : Low temperature environment (the toughness of carbon steel drops sharply below -20°C), hydrogen embrittlement (improper electroplating or pickling process), and internal defects of the material (pores, slag inclusions).

Features : The fracture is smooth without plastic deformation, often accompanied by sudden fracture.

reason :

• The friction of the wire rope causes the hook groove to wear (especially when lifting at a single point frequently);

• Pitting and stress corrosion cracking (Cl⁻ corrosion) in chemical/marine environments;

• Poor lubrication increases wear.

Material selection : DG20MnTiB and other low carbon alloy steels are preferred, with impact energy ≥ 27J at -40℃.

Structural optimization : T-section hook body (bending resistance increased by 30% compared with trapezoidal section), transition zone R angle ≥ 12mm.

Safety factor : According to FEM 1.001 standard, the rated load must meet ≥4 times the static load safety factor.

Load Control :

• Install an electronic limiter (such as a SICK load sensor) to automatically cut off power when overloaded;

• Non-standard operations such as oblique pulling and sudden braking are prohibited.

Regular testing :

• Magnetic particle testing (MT): Check surface cracks every 6 months (focus on hook neck threads);

• Ultrasonic Thickness Gauging (UT): monitor corrosion thinning areas (shortened to 3 months in chemical environments).

Scrap standards :

• Hook deformation > 10% of original size;

• Crack depth > 2mm or length > 10% of hook diameter.

Anti-corrosion treatment : hot-dip galvanizing (thickness ≥ 80μm) or spray polyurethane coating (salt spray test ＞1000h).

Lubrication solution : The hook neck bearing is lubricated with lithium-based grease (NLGI grade 2), and the wire rope contact surface is coated with graphite paste.

Intelligent monitoring :

• Strain gauge + wireless transmission to monitor stress distribution in real time;

• AI algorithm analyzes vibration spectrum and predicts fatigue life.

Low temperature conditions : Use austenitic stainless steel (such as 06Cr19Ni10) or perform a -50℃ Charpy impact test.

Corrosive environment : Use duplex steel 2205 or external cathodic protection (sacrificial anode method).

A port crane hook fracture accident :

• Cause of failure : fatigue crack at the root of the hook neck thread (the backing groove was not turned according to the standard) + long-term overload of 5%~10%.

• Improvement measures : Use a fully forged one-piece hook (to eliminate thread stress concentration) + install a wireless acoustic emission monitoring system.

Digital twin warning : Use ANSYS simulation to simulate stress cloud maps under different working conditions and predict high-risk areas.

Self-healing coating : Microencapsulated corrosion inhibitors are embedded in the coating and automatically released to repair after wear.

Blockchain traceability : records the entire life cycle data of the hook (smelting → forging → use) to ensure quality traceability.