Stainless steel seems like it’s a ubiquitous part of life. Whether we’re eating dinner, visiting a doctor or driving in our car, much of our daily activity is made possible (or at least safer and more convenient) thanks to stainless steel. What many people don’t realize is one of the most important factors that makes stainless steel so versatile is its ability to be cold worked.
Steel has been a part of human industry for millennia. Stainless steel, with its exceptional corrosion resistance, is a more recent development, having only been commercialized in the early parts of the 20th century. It quickly gained in popularity, transforming several industries, including architecture, engineering, food and beverage, transportation and more.
Only a truly versatile material would be able to impact our lives in so many ways. That’s why manufacturers and designers are increasingly looking to stainless steel for their applications. Because of its cold forming properties, stainless steel alloys can be cheaper to work with than you might realize.
What is Cold Forming?
Any time you’re working with metal, it’s necessary to form that metal in the desired shape. If you want to create an application on an industrial scale for commercialization, then whatever manufacturing method you use must also be duplicated on a consistent basis. One option for shaping metal is known as cold forming.
Also known as cold working, this method’s technical definition is a metalworking process in which the shaping occurs below its recrystallization temperature. While the recrystallization process is complicated to explain, it involves heating a material in order to form a new grain structure. Cold working, as the name implies, occurs at a lower temperature than this, normally at room temperature.
Cold forming metal will distort the crystal grains and inclusions, leading to the material becoming harder, stiffer and stronger. The drawback is that the metal becomes less elastic and cracking may occur. There are many different methods for cold working metal and it’s possible to create various complex shapes. The processes involved tend to be simpler and cheaper to perform than hot working methods.
Methods of cold forming include rolling, extruding, forging, swaging, heading, thread rolling, coining, bending, flanging, drawing, perforating, stretch forming and flattening.
What are the advantages of cold forming?
When deciding on the best shaping method for your application, you must take many factors into consideration. Generally, you want to use whatever method is cheapest and most convenient while still being reliable. Cold forming checks off many of these boxes for manufacturers.
Among its advantages, cold forming does not require heating. It’s not hard to see the benefits of avoiding high temperatures. When dealing with metals like stainless steel, hot working techniques can be a significant safety concern for workers, not to mention the energy costs involved. Being able to effectively work a metal at room temperature is obviously very desirable.
And while many assume that if you are trying to strengthen a piece of metal you’re going to need heat treatment, modern cold working methods can match the properties of thermal processing. In fact, in some circumstances, it may be more economical to cold work a cheaper metal than to heat treat a more expensive grade.
Other advantages of cold forming include a better surface finish, superior dimension control and less contamination. It tends to be easier and cheaper to reproduce cold forming techniques at scale. There is also less waste generated and shorter production cycles. When you add up all the cost savings involved with cold working it can become very significant, especially with large production runs.
Of course, there are some disadvantages as well. Working with metal at room temperature means the work piece is harder and tougher, so greater forces must be applied requiring heavier machinery. The metal is also less malleable than when it’s been heated, so there is less ability to shape the metal. That means that some dimensional requirements can only be fulfilled with higher temperatures.
Which alloys work best with cold forming?
It’s important to choose the alloy you use for any application very carefully. Every grade of stainless steel has its own unique set of properties and each one will respond differently to work hardening stresses. Since cold working is a form of stress, you need to know how your alloy will react when pressure is applied, and what are the best ways to maximize the strength of your work piece.
When hardening is your goal, austenitic stainless steels are probably your best bet. This family of stainless steel, comprising the 200 and 300 series of grades, is characterized as being non-magnetic and known for being both formable and corrosion resistant. These alloys are recognized for the rapid rate at which they can be hardened, making them suitable for applications that require high strength and corrosion resistance.
Another good alternative is duplex stainless steel, which combines the properties of austenitic and ferritic stainless steels. These alloys also tend to respond well to cold forming. It should also be noted that austenitic stainless steels can’t be heat treated, meaning that cold forming may be your only option.
Tour Trusted Services Provider
Cold forming offers manufacturers and engineers a wide range of possibilities when working with stainless steel. It is essential that you work with a metal supplier who has the experience and knowledge necessary to ensure that you get exactly the right metal for your job.
Clinton Aluminum, as the Midwest’s number one supplier of aluminum and stainless steel plate products, has the ability to quickly fulfill your orders both accurately and conveniently. Our sales professionals pride themselves on their ability to work with our clients to ensure they get exactly what they need. Our goal is to assist our customers through every step of their procurement process.
To learn more about how we can help you with your stainless steel supply needs, contact one of our friendly and knowledgeable representatives today.