Believe it or not, but according to recent studies of the WSA (World Steel Association), there are more than 3600 different steel grades that have their own unique properties. Just imagine that number. This number implies that steel products can be used in all the imaginable ways and there will always be steel product to suit your needs. Whether you need steel to manufacture a stove or to build the railroad, steel products got you covered.
This is fascinating and all, but how do you actually do it? How do you change the properties of the steel to suit your needs? The changes in chemical composition and the manufacturing process are the main ways of adapting the steel to your needs. If you take two exactly the same pieces of metal, from the same grades, with the same exact specifications and use different manufacturing process – the results will be very different. Two most important steel manufacturing processes are called hot and cold.
As you might have guessed, the hot-rolling manufacturing process involves lots of heat. While, cold-rolling manufacturing process, on the contrary, is done at room temperatures. While it may seem like the definitive deciding factor of the quality of the final product, don’t forget about the importance of the metallurgical aspect of the manufacturing. Different grades, compositions and ratings affect the final product just as much as the process that is used in their further manufacturing use. Yet all the steel can undergo these hot and cold manufacturing processes.
The main thing to keep in mind is that different types of steel and manufacturing methods have their own applications, for which they are best suited for. While we will talk about different types, ratings, compositions and specifications of steel in the near future, today we will focus on the cold-rolling process.
In general, steel that has been cold-rolled is more durable, harder and stronger than the hot-rolled steel. This is because cold-rolled steel is basically hot-rolled steel that went through further manufacturing. The process takes a bit longer than hot-rolling. Hot-rolled steel should undergo the cooling process, after which it will go through further rolling that is done at room temperatures. While the hot-rolling process shrinks the steel and makes it harder to control, the cold-rolling process is much more suited to create precise shapes and its surface is of much better quality, as the hot-rolling process makes it scaly. The term “cold-rolling” often refers to various processes that are done at the end of the manufacturing. This includes not only turning, grinding, sandbagging and polishing, but lots of other processes as well. While there may be many types of cold-rolling, the main purpose of them is the same, to get a more refined product.
What are the main selling points of the cold-rolling manufacturing process?
- The steel has much nicer surface. All the applications, in which the visual appeal of the product matters, use cold-rolling.
- The cold-rolling creates surfaces that are oily to the touch.
- The edges and shapes are properly defined.
- The tubes that are made by cold-rolling and much better, their uniformity is incomparable to hot-rolling.
Cold-rolling is the process to use when visual appeal, distinct and properly defined edges and shapes are of importance. Cold rolled sheets are harder and stronger than hot-rolled sheets. The main downside to the process is that, due to all the extensive treatments, the steel went through lots of internal stress, which may cause some warping down the line. However, this stress can be relieved during the manufacturing process before any damage is done.