Measures To Improve Fatigue Life Of Galvanized Steel Wire Rope
Due to the wide application of permanent magnet synchronous gearless technology, the miniaturization of the elevator mainframe has become the mainstream, especially the introduction of small engine room and engine room without elevator, making the traction wheel become smaller and smaller, and galvanized wire rope through the guide wheel More and more. This change in design greatly reduces the cost of the elevator system, but the use of galvanized steel wire rope conditions become more harsh, the impact of its life is greater. Tianjin Goldman Sachs Galvanized Wire Rope Company analyzed the factors that affected the fatigue life of galvanized steel wire rope. According to many years' practical experience, some measures to improve the fatigue life of galvanized steel wire rope were put forward.
First, the elevator traction system design optimization.
It is recommended to use a semicircular slot traction wheel because the galvanized wire rope is more susceptible to wear in the V-groove. For the semi-circular groove traction wheel, reduce the lower incision angle, is conducive to galvanized steel rope wear fatigue life. In addition, for the semi-circular groove traction wheel, when the actual diameter of galvanized steel wire rope and the same diameter, the contact area is the largest, the minimum contact stress, help to improve the fatigue life of galvanized steel wire rope. Rope groove is too large, galvanized steel wire rope is flattened; rope groove is too small, galvanized steel wire rope is extruded deformation, but also cause elevator noise. Galvanized steel wire rope itself under the conditions should be used in large diameter, small diameter galvanized steel wire rope fatigue life significantly reduced. In addition to considering the diameter ratio between the traction wheel and the galvanized steel wire rope, the ratio of the diameter of the traction wheel to the diameter of the outer wire of the galvanized steel wire rope should be taken into account. The ratio is not less than 650.
Second, a reasonable choice of galvanized steel wire rope.
In all the influencing factors, the purity of the steel wire and the final heat treatment before the wire drawing is critical. Galvanized steel wire rope for the elevator, the steel non-metallic inclusions control is very important, the sum of various non-metallic inclusions should not exceed 3. Phosphorus and sulfur are harmful elements in the steel, will lead to steel plastic, toughness decreased, thereby reducing the fatigue properties of galvanized steel wire rope. For galvanized galvanized steel ropes, the mass fraction of phosphorus and sulfur in wire rods should be less than 0.025%. Semi-finished steel wire The final heat treatment organization should be sorbite, it is not recommended to use normalizing treatment, because the steel wire is subjected to normalizing treatment of the organization mainly coarse sheet pearlite and ferrite, will lead to galvanized steel wire rope fatigue performance significantly reduced.