What Is Shot Peening?
Updated: December 22, 2023Shot peening is a popular method of increasing a piece of metal’s strength. It does this by counteracting internal stress with compression. The effects of this process include reducing the risk of stress corrosion failures and improving the metal’s longevity. Shot peening involves modifying the properties of the metal with pressurized materials to create a compressive residual stress layer. This process is the most economical way to extend your parts’ fatigue life.
Changing a metal part’s properties for increased toughness is a process that has applications in many industries. Some of those fields are aviation, energy and manufacturing.
How Does Shot Peening Work?
Shot peening is a highly controlled cold working process where technicians can control the materials they use and the shot’s intensity based on each project. This method has many similarities to shot blasting and sandblasting. Like both of these processes, shot peening blasts small materials with great force. However, shot blasting and sandblasting are both abrasive processes that clean a part’s surface. Instead, shot peening uses the impact of shot to change the metal’s properties. The shot can be glass, ceramic or metal.
Counteracting Tension With Compression
As metal cools, different areas of internal stress can pull apart from one another, causing cracks and breakage. Most objects weaken over time. If certain areas experience more stress than others, they’re more likely to become fatigued and break. Untreated metal is more vulnerable to early fatigue because it has uncompressed areas of stress. The uncompressed surface allows tension to pull the material apart, creating cracks.
Each tension is called a stress riser. Impacting the surface around those stress risers with pressurized material strengthens their bond and compresses the metal. This prevents separation. Thus, shot peening relieves internal stresses and prevents fissures by creating compression. This process works because compression is tension’s opposite.
Does It Remove Material?
Yes, shot peening can remove some material. Depending on the force of impact and the metal’s hardness, shot peening may remove some higher points of the material’s surface. Note that fine finishing can only remove a small amount of surface material. Deeper areas have higher levels of compressive strain, making them stronger and harder to remove in this way.
Shot peening will not remove existing cracks, but it will cover them. To make sure they produce the most reliable parts possible, technicians must inspect metal before shot peening to ensure they finish only whole, undamaged parts.
Contact Finishing Systems Today
Our company has over 40 years of experience finishing reliable parts for our clients. Finishing Systems’ job shop includes technicians with the expertise to provide services like shot peening for your specific needs. We’re proud to offer turnkey solutions and customized methods that meet and exceed our clients’ expectations. When you send us a sample part, we’ll develop a plan of action that prioritizes effectiveness and efficiency so you receive finished parts that align with your specifications as soon as possible.