Metallurgical industry shortcomings refers to the non-metallic materials in raw materials including debris, bubbles, the original loose, these. The reference material on the surface is the stress source, will cause the reference material and the base material in the middle of the page forced to cause fatigue cracks. The selection of vacuum pump smelter, vacuum pouring and other countermeasures can further improve the quality of stainless steel plate.

Corrosive material When the spring works in corrosive material, because the surface causes crack corrosion or surface dislocation is corroded and becomes a source of fatigue, it will gradually expand and cause rupture under the effect of variable in-situ stress. For example, the fatigue limit of spring steel working in water is only 10%~25% in the air. The harm of corrosion to the fatigue strength of spring is not only related to the efficiency frequency of spring under variable load, but also related to the service life of the spring. Therefore, when the design scheme calculates the spring damaged by corrosion, the service life should be taken into account in the work.

The spring working under the corrosion standard, in order to better ensure its fatigue strength, can choose the raw materials with high corrosion resistance, corrugated spring such as stainless steel plate, non-iron metal materials, or the surface of the protective layer, such as coating, air oxidation, electrostatic spray, paint, etc. The practice shows that cadmium plating can further improve the fatigue limit of spring.

The fatigue strength of temperature carbon steel decreases from the indoor temperature to 120℃, increases from 120℃ to 350℃, and decreases after the temperature exceeds 350℃. There is no fatigue limit at high temperature. Springs working under high temperature standards should take into account the choice of wear-resistant steel. The fatigue limit of steel increases under the standard of less than indoor temperature.