low temperatures, the brittleness of the material is very sensitive to
surface defects. Therefore, the surface quality of the material should
be strictly required.
At low temperatures, the modulus of
elasticity and the coefficient of expansion of the material do not
change much and may not be considered in the design.
of spring steel, hardness (ie, strength) selection should be based on
spring bearing properties and the size of the stress. However, the
relationship between hardness and plane strain fracture toughness is
From the curve relationship, it can be seen that
as the hardness increases, the plane strain fracture toughness (KIC)
value decreases significantly. This means that in determining the
hardness value of the spring, the hardness of the spring should be lower
if the spring characteristic requirements are satisfied.
selecting springs for spring manufacturers, attention must be paid to
the hardenability of the steel. The extent to which the cross-section of
the spring material is hardened and hardened is extremely relevant to
the quality of the spring.
Electric springs that are springs
themselves as conductors, or springs that operate in water (including
seawater) and water vapor environments under conditions of variable
humidity, are generally copper and gold materials.
that work under other corrosive media such as acid contacts are
generally made of corrosion-resistant materials such as stainless
acid-resistant steel or nickel alloy. Springs used in general
environmental media conditions, the choice of ordinary spring steel,
made of springs in the surface after rust coating or plating
(galvanizing, cadmium plating, copper plating) method of corrosion
Springs used in scales and meters, in order to meet
their accuracy is not affected by temperature changes, generally use a
constant elastic alloy with minimal change in elastic modulus and
In the case of springs requiring special
qualities such as light weight, insulation, anti-collision, and
anti-corrosion, reinforced plastics can be used. At present, the more
suitable plastic spring is epoxy resin, phenolic resin as the matrix,
and glass fiber reinforced thermoset reinforced plastic GFRP.
Anti-vibration rubber can also be used to make various types of rubber
At present, the processing equipment and processing
lines of mechanical springs are developing toward the depth and breadth
of numerical control (NC) and computer control (CNC). However, with the
changes in spring materials and new geometric shapes, the processing
technology has also developed.
1) Variable spring outer diameter,
variable pitch, and variable wire diameter (three-variable) Suspension
springs achieve moldless machining. Since the development of the
three-variable springs, taper steel rods have been used for winding on
CNC lathes, but the yield and price are not satisfactory. It is now
replaced by a coil spring machine under heating conditions to control
the roll speed and pull-out force to obtain the required cone shape and
quench with the process residual heat.
2) Hollow-stabilized spring rods are rolled and welded using low-carbon boron steel.
The torsion bar is made of high-purity 45 steel. After high-frequency
quenching, the surface has a high hardness and a large residual
compressive stress, thereby improving the fatigue life and the ability
to resist relaxation.
4) The widely used sheet springs for
electronic products are basically formed by stamping and automatic
bending. At present, it is mainly the development of joint technology of