Leaf Spring Steel Welding
Welding leaf spring steel is a challenging task, even for experienced welders. Spring steel is a special type of material that is used to make springs and other products that require elasticity and resistance to deformation.
It’s highly efficient in its ability to absorb energy from an applied force and return it when the force is released.
As such, welding with this type of metal requires great care so that it remains intact and retains its shape during the welding process.
To successfully weld spring steel, you must be aware of the physical properties of the material before beginning the job.
Spring steel has a high carbon content, which means it has a higher tensile strength than mild steels or stainless steels. This makes it difficult to control during welding due to its tendency towards work hardening quickly as heat is applied.
Can you Weld leaf Spring Steel?
Especially with spring steel, the answer arises again and again as to whether it can be welded?
- Is it ok weld spring steel?
Whether this is possible and how to recognize which steels are weldable, you can find out in detail in this article. In addition, which criteria still have to be taken into account for weldability.
Weldability of spring steels & Leaf Springs
The weldability of spring steels can be different, depending on the alloy. So you always have to check the type of spring steel material.
Spring steels are mainly following types:
- Carbon steel spring steel,
- Corrosion resistant spring steel,
- Durable spring steel,
- Heat-resistant spring steel,
- Low-temperature spring steel,
- Non-magnetic spring steel,
- Seawater resistant spring steel,
- Electrically conductive spring steel,
- spring steel for aerospace applications.
Whether a steel is weldable or not depends primarily on its carbon content.
Basically, it can be assumed as a guideline that steels with a carbon content below 0.22 % are easy to weld, up to about 0.3 % carbon content steels are usually weldable after some preparatory work (preheating, stress relief annealing).
Spring Steel Carbon Equivalent
Carbon Equivalent of a steel is good indicator for its weldability. A carbon equivalent weldability factor applies to carbon steel, cast iron and low alloy steel and not applicable for high alloy steels such as stainless steel or non-ferrous metals.
To make this a little easier, there are different ways to calculate the so-called carbon equivalent from the alloying components.
Read my article What is Carbon Equivalent in Steel?
At the end of the calculation, a value is obtained for which similar guidelines apply as for the carbon content, but the values are slightly higher:
- up to 0.45 % good weldability
- up to 0.65 % basically suitable for welding
- from 0.65 % only weldable with very high effort or not at all (hardening cracks possible)
Welding Leaf Spring Steel Procedure
- Find out the type of spring steel.
- Make a complete joint penetration weld joint configuration as springs are under cyclic loading. Making a PJP weld is not advised.
- For high carbon spring steel, apply welding preheat.
- Remember, welding area in a spring steel will have different properties than the spring, so welding repair must not be the first alternative. Carry out welding repairs only in limited conditions.
- Weld using E7018 or any other high toughness weld filler rod such as E309-15 or ER309.
Should you Weld Leaf Spring Steel?
Leaf Spring steel is a high-carbon alloy that can be difficult to weld due to its composition and the amount of heat required for the process.
Despite this challenge, welding leaf spring steel can be welded although it will have varied properties in the weld zone, heat affected zone compared to the spring steel material.
So, welding should only be carried out if there is no other option. The strength of the weld will also be very low compared to the spring steel original material.
So, consider all above factors before you make a decision to perform the welding.
Leaf Spring welding – useful or not?
The spring of the car is an important element of the vehicle. It is made of special spring-spring steel and thereby takes on the main loads when the car passes on uneven roads.
Unfortunately, over time, the spring loses its elastic properties and there is a gradual destruction of the metal – fractures, cracks, corrosion.
If you do not repair the spring in a timely manner, it can fail at the most inopportune moment.
Using the latest equipment and modern materials, it is now much more profitable to repair an old spring than to buy a new one.
And if the welding of the spring is performed qualitatively, then it is impossible to find their fundamental difference!
Welding and the subsequent heat treatment in terms of operational properties is not inferior to new spring sheets when welded using the right welding filler followed by right heat treatment.