Reduction of elasticity of stainless steel wire rope

I. Causes and Mechanisms Behind the Reduction in Elasticity of Steel Wire Ropes

1. Material Fatigue and Microscopic Damage

Steel wire ropes, when subjected to repeated bending and stretching, experience dislocation accumulation and micro-crack propagation within the 

individual wires. Studies show that when the cyclic load reaches 60% of the fatigue limit (as per ISO 4308:2018), the elasticity modulus of steel wire 

ropes decreases by approximately 15%-20%. Long-term overload, such as exceeding the rated load by 110%, accelerates this elasticity loss rate by 

2-3 times.

2. Corrosion and Friction Wear

Humid or salt-laden environments accelerate the oxidation of steel wire rope surfaces, leading to a reduction in cross-sectional area. According to 

the Steel Wire Rope Association of America, untreated steel wire ropes used in marine environments lose 40% of their elasticity after one year of use. 

Additionally, friction between strands can cause the lubrication film to fail, further accelerating rigidity development.

3. Structural Deformation and Abnormal Loads

Using a pulley with a diameter smaller than 18 times the rope diameter can cause plastic deformation of the steel wire rope. For example, a port 

crane, which used a non-compliant pulley diameter, experienced a 28% reduction in elasticity modulus after only 6 months of operation.

II. Key External Factors Affecting Elasticity Performance

1. Environmental Conditions

The following table outlines the rate of elasticity decay in various environmental types compared to standard conditions:

III. Solutions and Engineering Practices

1. Optimal Selection

Prefer steel wire ropes with a 6×36WS construction. Their elasticity retention rate is 30% higher than the 6×19S construction, based on tests 

conducted by the German Steel Wire Rope Technical Center (2021).

In corrosive environments, use ropes with a galvanized coating of ≥80g/m² (compliant with GB/T 8918-2020).

2. Scientific Maintenance

Lubricate the ropes every two weeks using a highly penetrative synthetic grease, such as Shell Darina R, which can reduce friction loss by 60%.

Regular Inspections: Use magnetic flaw detectors to check for localized wire breaks. Replace the rope if more than 10% of the individual wires are 

broken.

3. Load Management

It is recommended to maintain the actual load within 20%-30% of the rope’s breaking strength (according to Crosby Group’s safety standards). 

This range ensures the most stable elasticity performance over time.

Understanding the factors that influence the elasticity of steel wire ropes is crucial for extending their lifespan and improving safety. By addressing 

material fatigue, corrosion, and mechanical wear, and implementing regular maintenance, appropriate selection, and load management strategies, 

operators can significantly enhance the performance and reliability of steel wire ropes.