Importance of surface finish in stainless steel
In the fast-moving pace of the fastener world, we might hear things like: “The stainless steel you supplied has gone rusty. This can't be stainless. What's gone wrong? How can we fix it? Can we check if the material chemical composition is correct?"
Although the common objective of stainless steel applications is to work perfectly as intended by the designer and end user, there are a significant number of instances where one could be disappointed by the performance of the material. These disappointments tend to fall into only a few basic categories, but it is critical that we understand the possible causes which lead to such a situation. In most cases, a little basic knowledge would have prevented or significantly improved the situation.
The definition of stainless is known as without stain or blemish in general. For this case, the stainless steel has a function which builds around a certain resistance to stain or corrosion as a primary function. The most common stainless steel contains both chromium (between 18–20%) and nickel (between 8–10.5%) as the main non-iron constituents. It is less electrically and thermally conductive than carbon steel and is essentially non-magnetic. It has a higher corrosion resistance than regular steel and is widely used because of the ease in which it is formed into various shapes. In the industry, there are also many different types of effect of surface finishes on the corrosion resistance of stainless steel.
This paper will show the importance of passivation, polishing medium and surface profile on the corrosion resistance of stainless steel. In addition, it will also demonstrate the importance in obtaining a correct specification of architectural features where cosmetic appearance is a dominant factor.
For the purpose of understanding the topic in depth, we will focus on two key areas of discussion:
- Is passivation in stainless steel necessary?
- Importance of surface finish in stainless steel