Production Process of 35W×K7 Structure High-Strength Large-Diameter Steel Wire Rope
The steel wire rope adopts a compact strand production method, with the strand compaction rate controlled in the range of 6.5% to 8.5%, improving the breaking strength of the steel wire rope. The inner layer of strands uses a small twist pitch of 6.5–7.0 times, while the outer layer uses a larger twist pitch of 7.0–7.5 times. During the formation of the steel wire rope, the inner strands are not pre-deformed, while the outer strands are sufficiently pre-deformed. The internal and external strands are twisted and formed simultaneously to ensure a balanced torque between the inner and outer layers of the steel wire rope. The produced steel wire rope has uniform and consistent strand gaps, with no visible cracks to the naked eye. The steel wire rope is not loose, has a stable structure, high breaking strength, excellent abrasion resistance, and good rotational resistance. The contact area between the steel wire rope and the drum or pulley is large, which enhances the service life of the rope.
The steel wire rope has a diameter of 52mm and a tensile strength of 1960 MPa. The process includes the following steps:
(1) Strand Configuration
The strand configuration process parameters are as follows:
- Center strand: 3.50/3.15mmFirst layer strand: 3.20/2.93mmSecond layer large strand: 3.20/2.93mmSecond layer small strand: 2.35/2.15mmOuter layer strand: 3.15/2.85mm
During stranding, the wire size is selected based on the strand diameter, and the wire guide plates are used in pairs with proper compression. There should be no wire breakage or damage during production, and the strands should not exhibit defects such as burrs or oval shapes. The stranding process parameters are:
- Center strand: Strand diameter 9.80mm, twist pitch 83mmFirst layer strand: Strand diameter 9.06mm, twist pitch 86mmSecond layer large strand: Strand diameter 9.06mm, twist pitch 86mmSecond layer small strand: Strand diameter 6.65mm, twist pitch 63mm Outer layer strand: Strand diameter 8.85mm, twist pitch 84mm
The strands are compacted using a roller compaction process. The compaction rate is controlled in the range of 6.5% to 8.5%. After compaction, the steel wires inside the steel wire rope are in surface contact with each other.
(4) Closing
The rope laying is performed using a series machine for one-time stranding. First, the 19W×K7 inner layer rope is twisted on the first bobbin, using a 19W splitting plate without pre-deforming the strands. After passing through the splitting plate, the strands naturally come together at the wire guide plate. Then, the 35W×K7 outer layer rope is twisted on the second bobbin, using an 18# head, with a working roller diameter of 40mm and a roller end distance of 0.75 times the rope’s twist pitch. The bending depth is 1.1 times the rope’s diameter. The rope diameter deviation is controlled within the range of 0 to +4%. The twisting process parameters are as follows:
- Inner layer rope diameter: 37.6mm, twist pitch multiple 6.5–7.0mm, twist direction ZS
- Outer layer rope diameter: 52.0mm, twist pitch multiple 7.0–7.5mm, twist direction SS
