There are a lot of important issues and basics that you should know when it comes to machining stainless steel. A lot of things can influence the way steel is machined, it is a strong material so it’s not something that should be taken very lightly. There are a few different points that we should go over below so you can get a better understanding of what goes into the process of machining stainless steel.
The most common stainless steels that are frequently used in machining are what we know as “austenitic” types which come in the grades 304 and 316. They are considered the most popular and most widely used because they have excellent work hardening rates and don’t chip as easily which is something that can happen during this process.
The first thing you should know when it comes to machining stainless steel is you want to be sure that there is no rubbing or dwell being caused by the machine tools or any vibrations. Any machinery that is being used for the stainless steel needs to be able to make the cuts without slowing the entire machining process down. Some machinery may not be able to complete this task – if machinery has training lathes or you are using milling machines, some of this might not be able to cut through tougher steel or metals. It’s important to remember what to avoid which can include overhanging equipment such as the tool shank or tool box. You also want to avoid vibrations, your arbors should also be as short as possible so you can support the machinery and steel properly. If your machinery has started making squealing noises or any abnormal noises, you should make sure that no parts need to be replaced.
There are two popular machining stainless steel ways which involve using high speed steel or either cemented carbide tools. When you need machining operations that need high feed and low speed machining, then high speed steel is a good option for you. They are good at variable cutting edge stresses which are what is needed to form complex tool shapes. If you need higher speeds and higher feeds, then the better option for you would be cemented carbide tools. Coated cemented carbide tools have the added benefit of being resistant to wear and breakage as well as being able to cut at higher speeds than the uncoated versions. The machinery and tools you choose should be based on what fits your particular needs.
If you are someone who already cuts and machines stainless steel then you know how important it is for your tools so remain sharp. It extends the life of your tools, the finish of the product comes out much cleaner, accuracy is much more precise and productivity flows much more efficiently. Using blunt tools can lead to damages, wasted energy and slower productivity. You should set a routine in place to sharpen your tools and machinery on a regular basis. The geometry of your tools is another important factor you should consider as it can minimize swarf build-up which can lead to poor surface finish and other issues.
Cooling and lubrication are also important things to remember when talking about machining stainless steel. Overheating can lead to a lot of problems including distortion of the machinery and the steel. Mineral oils or water soluble emulsifiable oils are used to cool down stainless steel machinery. Mineral oils are diluted with paraffin, the ratio of paraffin to oil changes depending on the speed of work and light feed. Emulsifiable oils are diluted with water and are considered more cooling than the mineral oil and paraffin mix. The ratios of oil to water are pretty standard but the mix must be right so that the emulsion reaction can happen correctly.