MT/T 716-2019Technical delivery requirements of steel wire ropes for coal mine hoisting (English PDF)

3.1 Steel wire for rope making

The steel wire used for rope making shall comply with the requirements for important purpose steel wire in GB/T 8919.Compacted strand wire rope wires shall comply with the requirements for important purpose steel wires in YB/T 5343.

3.2 Rope core

3.3 Grease

Unless otherwise required by the purchaser, the surface of the wire rope shall be evenly and continuously coated with anti-rust lubricating grease. When the purchaser requires the steel wire rope to have friction-increasing performance, the steel wire rope shall be coated with friction-increasing grease and there shall be no leakage.

4.1 Basic requirements

4.1.1 Wire ropes shall have mining product safety signs.

4.1.2 Wire ropes shall have quality certificates. Among them, the requirements for steel wire ropes shall comply with the implementation standards and requirements for safety signs of mining products.

4.2 Requirements for wire ropes

4.2.1 Diameter

4.2.1.1 Nominal diameter

The nominal diameter shall comply with the requirements of GB/T 8918 and YB/T

5359, otherwise it shall be agreed upon by both parties. The nominal diameter shall be indicated on the wire rope quality certificate.

4.2.1.2 Diameter deviation and out-of-roundness

Diameter deviation and out-of-roundness are shown in Table 1.

4.2.2 Length

4.2.2.1 Nominal length

It shall be agreed between the supplier and the purchaser and specified in the order contract. All specimens shall be included in the order length.

4.2.3 Weight

4.2.3.1 Reference weight

In kg/100 m as the unit, it shall comply with the provisions of GB/T 8918 and YB/T

5359.Otherwise, it shall be agreed upon by the supplier and the purchaser and specified in the contract.

4.2.4 Surface quality and twist quality

They shall comply with the provisions of Annex A.

4.2.5 Not loose

The wire rope shall not be loose (except for multi-layer strands, four-strand fan strands and braided wire ropes).

4.2.6 Elongation

Permanent elongation in use shall be mutually agreed upon.

4.2.7 Nominal tensile strength and breaking force

4.3.3 Tensile strength and breaking force of steel wire

4.3.3.1 Nominal tensile strength

The nominal tensile strength of the steel wire shall comply with the provisions of Table

2 and shall be stated on the steel wire rope quality certificate. The values in Table 2 are the lower limits of tensile strength. The upper limit is equal to the lower limit plus the strength tolerance specified in Table 4.

4.3.3.2 Strength tolerance

The strength tolerance shall comply with the requirements in Table 4.

4.3.4 Repeated bending

The number of repeated bending times for steel wires with a diameter greater than or equal to 0.50 mm shall comply with the requirements in Table 5.

5.1 Inspection and testing of wire ropes

5.1.1 Measurement of diameter

Wire rope diameter shall be measured with a vernier caliper with wide jaws. The minimum width of its jaws shall be sufficient to span two adjacent strands. The minimum graduation value of the measuring instrument shall not be less than ±0.02 mm.

5.1.3 Measurement of weight

Measure the total weight of the wire rope (including spool, hook and packaging material) in kg. Subtract the weight of the reel, chain hook and packaging material from the total weight and divide it by the actual measured length of the wire rope (in hundreds of meters). The resulting quotient is the actual unit weight of the wire rope, expressed in kg/100 m.

5.2.2 Tensile test

Carry out according to the method specified in GB/T 228.1.

5.2.3 Repeated bending test

Carry out according to the method specified in GB/T 238.

5.2.4 Torsion test

Carry out according to the method specified in GB/T 239.1.

5.2.5 Zinc layer weight test

Carry out according to the method specified in GB/T 1839.

5.2.6 Eligibility conditions

5.2.6.1 Method 1

6.1 General

6.1.1 Each wire rope shall undergo acceptance inspection and inspection before hanging.

6.1.2 Acceptance inspection and pre-hanging inspection shall be proposed and sampled by the user.

6.1.3 Acceptance inspection and pre-hanging inspection shall be carried out by qualified inspection organizations authorized by the department responsible for supervision and management of production safety.

6.2 Sampling method and sampling quantity

6.2.3 Zinc layer weight test

The test quantity is 10% of the total number of steel wires of the same nominal diameter in the wire rope (selected from the specified number of strands). Round to an integer according to GB/T 8170.

6.3 Rules for judgement

6.3.1 Method 1

6.3.2 Method 2

6.3.2.1 Round strand wire rope and special-shaped strand wire rope

If the breaking tension of the steel wire rope is qualified and the split wire test meets the qualification conditions, the steel wire rope will be judged to be qualified. If the breaking tension of the wire rope fails or the split wire test fails to meet the qualification conditions, the wire rope will be judged to be unqualified.