Stainless steel shot peening: why is it important in steel processing?
Tradition, innovation and technology
In-depth knowledge of material properties is essential to provide a quality and durable product.
Research and development in the field of stainless-steel processing, the protagonist material of STRAL's production, has over time found the recipe to provide the most valuable and durable material on the market, especially when it comes to outdoor use.
Stainless steel, a material that by nature embodies the concept of versatility, is the subject of constant research in the field of surface finishes, and the results benefit the most diverse sectors: from construction and architecture to the naval sector and even the household appliance sector.
Over the years of using this material exclusively in the production of luminaires, STRAL has specialized in the technical areas concerning the properties and processing that are related to this world.
Shot peening is a cold mechanical process. The idea behind it is like the process that blacksmiths over the centuries used to hammer metal repeatedly to gradually improve its strength.
This treatment improves the fatigue resistance of metal parts and is the most effective technique to achieve this.
It has been proven by academic research studies and practical use that shot peening is unrivalled when it comes to hardening metal surfaces. This process increases the durability of the metal.
The goal is to give a uniform, quality aesthetic finish and increase mechanical resistance to stress.
Shot peening consists of hammering the surface by means of a violent jet of micro spheres.
Shot peening machines shoot the jet towards the workpieces via one or more rapidly rotating centrifugal impellers, or via compressed air.
Materials such as cast iron, steel, glass, or ceramics can be used for the shot. And shot peenable workpieces can be made of iron, steel, or stainless steel.
Shot peening causes a surface compression of the metal as its jet induces plastic deformation.
This process serves to improve the surface stress distribution of the material, increasing the fatigue strength of the workpiece.
In fact, machining produces residual compressive stresses in the surface and underlying layers that can decrease internal stresses when the workpiece is subjected to stress.
Many manufacturing processes, such as welding, lead to a reduction in fatigue strength. These processes are essential, but ultimately reduce the life of the material. Therefore, shot peening has become a standard in STRAL production.
When it affects the finishing of austenitic stainless steel, the shot peening process will result in hardening of the surfaces and, in some cases, a reduction of stresses in the part.
To understand the importance of this process and the value it brings to STRAL luminaires, one only must consider that shot peening is widely used for essential metal components such as bearings, shafts, and gear teeth.
Stainless steel shot peening is carried out after the cutting, welding, and cleaning processes the luminaire undergoes.
This process restores most of the fatigue strength that disappears during these other processes. When it comes to strength, durability and safety, stainless steel shot peening is an absolute leader.