Difference Between Hot Rolled and Cold Rolled Steel
The type of steel you are planning to use for your project is very important. There are different applications and different ways in which you can use steel materials and it is important to know the difference between them. If you are just starting off, then the most important thing you should know is that there are two main methods of manufacturing rolled steel. These methods are called hot and cold.
The better you know the difference between them, the better will be your company’s performance in dealing with them. Today we will help you with just that, to understand the most important differences between these two manufacturing methods and out the main ways of their use.
Let’s start off by talking about Hot-Rolled Steel.
Hot-rolling revers to a process in which the steel is rolled at a high temperature that typically exceeds 1000° F. The main purpose of that is to go beyond the material’s recrystallization point. As a result, the steel becomes more malleable and can be easily shaped in whatever form you want it to be. This method is the best when it comes to producing large quantities of steel products. After the heating process, the steel is left to “normalize” in a roomed temperature. This process eliminates any stresses that may have arisen during the quenching and hardening processes. The downside is that, when the steel gets back to normal temperature, it will shrink, which makes it hard to control the final product when it comes to size and shape. The process of hot rolling leaves a scaly appearance to the surface. If a customer needs the steel to look presentable, then this effect can be eliminated in various ways. These include sandblasting, grinding and pickling.
So, in summary, this process provides with a sturdier product that is better suited for situations, in which overall shapes and their preciseness are not as important. Thus, hot rolled sheets are mostly used as structural components for applications like: subway tracks, various equipment that is used in agriculture, automotive industry, and so on.
What about the process of Cold-Rolling?
It goes without saying that the manufacturing process of cold-rolled sheets is quite different. Yet, while you might have imagined this process in a different way, it refers to steel being pressed with a roller. And no “cold” is involved, the entire process is done at room temperatures. This process increases the strength of the steel by around 20 percent. This is because the steel is going through a series of hardening processes.
Cold-rolling allows to create shapes and forms that are more precise and accurate. And, because the process doesn’t involve high temperatures, as it does in hot-rolling, the steel won’t shrink and won’t cause any problems with that. The main selling point of the steel that has been cold-rolled is its visual appeal.
The main downside of cold-rolling is the limitations of the manufacturing process. This mainly concerns the shapes of the final product. Cold-rolling is bound to certain shapes, those being square, flat, round and everything in between.
Which one do I need out of the two?
Now, the question of “which of the processes is better suited for me” arises. In general, if you are working with large products, visual appeal of which is of no importance, then you should choose the hot-rolling process. If you are working with smaller products that require precision and exact shapes, then the cold-rolling process will be the best at it.
I hope that you have enjoyed this article and learned a few new things about the steel-rolling processes. We wish you all the best in your future projects.