Spring sheets play a large or small role in our daily lives, and have different shapes and structures depending on their uses. So what are the characteristics or requirements of its material and hardness? Let us discover together.
Spring leaf material:
Carbon spring steel: The most commonly used materials are: 65#, 70#, 65Mn, 82B, 72A, and 72B steel wire. It is characterized by low plasticity, strong elasticity, and strong stress resistance. Alloy spring steel: Alloy spring steel is a type of steel used to make springs or other elastic parts. It has high yield point, yield-to-strength ratio, elastic limit, and fatigue resistance.
According to the characteristics of the material, it is used in actuators in different environments. Spring leaf is widely used in various contact devices, and the simpler straight cantilever leaf spring is the most widely used one. The contact pad must have low resistance, so it is made of bronze.
According to the performance requirements, the heat treatment requirements of the spring leaf are put forward. The hardness after heat treatment can generally be determined to be between 36-52 HRC.
Technical requirements for spring blades
1. The radius of the bent parts. When the spring leaf is formed, most of it should be curved. If the radius of curvature of the curved parts is relatively small, these parts will generate great stress. Therefore, if the bent portion is to avoid greater stress, the bending radius should be at least 5 times the plate thickness.
2. Stress concentration at the notch or hole. Spring leaf often has stepped parts and openings, and stress concentration will occur in the stepped parts where the size changes drastically. The smaller the hole diameter, the larger the plate width, and the larger the stress concentration coefficient.
3. Spring leaf shape and size tolerance. Most springs are stamped, and the shape and size suitable for stamping should be considered when designing. At the same time, full consideration must be given to dimensional tolerances such as the rebound of the spring leaf during bending and deformation during heat treatment.