Precautions For Spring Processing

1. The surface treatment of the spring is generally phosphating, and other treatments are also possible. Where the coating is zinc and cadmium, the hydrogen removal treatment should be carried out after electroplating. After the hydrogen removal, 3% (no less than 3 pieces) should be pumped for retesting and standing treatment, and there should be no breakage during the retesting. The surface of the spring should be cleaned of dirt, salt marks, and oxide skin. The method can be cleaned by sand blowing or gasoline, but pickling cannot be used.

2. Springs without support rings and springs with too thin wire diameters should not be welded with spring heads, but the wire ropes at the ends should not have obvious looseness and should be deburred. For multi-strand springs whose head needs to be welded, the length of the welded part should be less than 3 times the cable diameter (the longest is not more than 10 mm). The heating length should be less than one circle, and it should be polished smooth after welding. During gas welding, the welding part should be partially annealed at low temperature.

3. According to the product requirements, the spring support ring can choose two methods: cold and hot. It is not allowed to heat the spring until it sparks or turns white, and the temperature of the silicon-manganese steel shall not be higher than 850℃. The support ring and the effective ring should be in effective contact, and the gap should not exceed 10% of the nominal gap between the rings.

4. The characteristics of the multi-strand spring can be determined by adjusting the lead, and the cable distance can be adjusted as necessary when winding. The screw distance can be 3~14 times the diameter of the steel wire, but generally 8~13 times is better. The spring force is also closely related to the free height, the end ring, the outer diameter and the performance of the steel wire, which can be changed by adjusting one or more of them.

5. The compression time of important springs is 24 hours, and the compression time of ordinary springs is 6 hours or 3 to 5 times continuously, and each time is kept for 3 to 5 seconds. When pressing, the gap between the spring and the mandrel should be 10% of the diameter of the mandrel. If the gap is too small, it will be difficult to operate, and if the gap is too large, the spring will be easily bent and deformed. If one of the springs is broken during compression, the rest should be reprocessed.

6. For multi-strand springs with large H0/D2 values, the spring should pay attention to its deformation during heat treatment, consider whether to wear the mandrel and pay attention to the placement method, and select suitable heat treatment equipment. Under the condition that can be repaired, multiple tempering and hot pressing can be carried out to achieve the purpose.