Stainless steel is a metal alloy with wide applications in many industries due to its unique features. However, depending on the industry, knowing the right techniques for effective stainless steel marking is necessary.
Many marking techniques are applicable in all types of materials alongside popular ones like stainless laser engraving. However, in terms of stainless-steel marking, there is little restriction. For example, it is not ideal for engraving stainless steel if there is a need for its anti-rust and anti-corrosive properties. Therefore, this article will introduce the stainless steel marking techniques and how to choose the right one.
Stainless Steel Properties
Before getting to know the right stainless steel marking techniques to use, it is important to talk about the different properties of the material. Unlike other materials, stainless steel does not tarnish either by rusting or corrosion over time. This is the most important characteristic of stainless steel as it determines its use and the marking method to use.
Also, even though stainless steel boasts high tensile strength, it has lightweight. Consequently, it is applicable in many industries, such as the automotive and aviation industries.
What Methods Can We Use For Stainless Steel Marking
Stainless steel material is popular among many industries because of its anti-rust and anti-corrosive properties. However, these two properties play a huge role in the marking method and the machine you can use.
The most important thing to note is that stainless steel has coatings by which it can avoid corrosion (although there are different grades of steel). Therefore, the method and machine to use should not alter this composition or remove the layer where the two properties are useful.
Many marking processes are available for use in stainless steel marking. However, not all of them are compatible with stainless steel. For example, marking methods like inkjet printing needs heavy maintenance and consumables. They can also lead to frequent downtime.
Two important marking methods have been highly utilized in stainless steel marking; Laser marking and dot peen marking. Below is a thorough explanation of how the two methods work.
Stainless Steel Laser Marking
Stainless laser marking processes are common methods used in different scenarios. However, their use depends highly on the grade of stainless steel available and the use. Consequently, there are five laser marking methods for stainless steel marking.
Laser Annealing/Stain Marking
Laser annealing is a non-penetrative and non-degradative laser marking method involving a laser beam to change a material’s color.
The process is achieved by heating the material surface till an oxide form. The type of color obtained depends highly on oxide thickness, the grade of stainless steel, and the laser beam temperature. Common colors achievable with the process are gray, dark brown, and black. You can achieve a wider range of colors with powerful fiber laser machines. However, these machines are difficult to use because they have too many complicated laser settings.
Laser annealing is the most common method used in stainless steel marking because it is non-degradative. Consequently, it does not affect the stainless-steel material.
Laser Etching
Laser etching is another stainless marking process popular for its speed, versatility, and durability. The process involves using a laser etching machine to laser etch stainless steel by delivering high energy on the stainless steel material. Consequently, the stainless steel surface melts and expands. Etching is commonly used to produce permanent markings such as data matrix codes, serial numbers, barcodes, and logos.
Dark Marking
Dark marking involves roughening the surface of the stainless steel material and applying color to it. The “color” is a function of the oxide layer with stain marks or the color or reflectivity of the underlying surface with ablation markings.
Due to the roughening up, the stainless steel material is trapped and colored. In addition, because of the procedure involved in stainless steel marking via laser dark marking, it is not ideal for some industries, such as the medical industry, due to the need to maintain equipment sterility.
Laser Ablation Marking
Laser ablation involves removing a thin layer of stainless steel to create a light-colored contrasting mark. The process requires little heat and little or no penetration into the material and is characterized by a faster marking speed, high peak power, short pulse width, and lower laser power output.
Using ablation marking comes with understanding the properties of stainless steel and its uses. However, ablation marking is not ideal in areas where the outer layer of the stainless steel responsible for its anti-corrosive properties is important. This is because it can lead to rusting of the material.
Laser Engraving
Laser engraving uses an engraving machine to create deep marks on stainless steel materials. It is durable and long-lasting, achieved using a stainless laser engraving machine with high laser power and lower marking speeds.
Laser engraving involves the removal of the surface of the material. Therefore, it is not a readily used method for stainless steel needed for its anti-corrosive effect. Most industries would rather use stainless steel marking methods such as laser annealing than laser engraving stainless steel.
Evaluating the Use of Laser Marking Methods With Stainless Steel
Laser marking methods are popular ways of marking stainless steel in different industries. However, depending on the type of methods involved, there are different advantages and disadvantages. Below are the advantages and disadvantages of using the method in stainless steel marking.
Advantages
Laser marking methods produce a permanent on the stainless steel’s surface.
They do not require application and cleanup like the marking compound
Laser marking methods are precise and produce markings of high contrast.
Disadvantages
The stainless steel material’s surface might be removed depending on the laser marking method. Consequently, it will lead to the loss of anti-rust and anti-corrosive properties. An example is the use of a laser engraver for stainless steel marking. Also, it can lead to a higher cost
Fiber Laser Machines
The most powerful and multifunctional solutions today are based on fiber lasers. The fiber system is perfect for commercial and industrial use, the newest laser etching stainless steel system there. HeatSign’s fiber lasers marking machines, such as the 30W and 50W Fiber Laser Engraver, apply high-quality engravings and add extra advantages for the user:
Dot peen marking is another stainless steel method involving a dot-peening machine striking the stainless steel surface. This removes a small part of the stainless steel with every hit. Successive hits will form a dot matrix which becomes the mark itself.
Because of the successive hits, the dot peening marking system is very effective in deep stainless steel marking. However, deep marking the material depends on material hardness, support tooling, and stylus properties.
Types Of Dot Peen Marking Tools You Can use with Stainless Steel
You can use three types of dot peen marking tools with stainless steel. They are:
Pneumatic dot peen markers
Electromagnetic dot peen markers
Scribing
Each dot peen marking tool has its application and requirement. Nevertheless, they are all applicable to stainless steel.
How to Choose the Right Dot Peen Marking Machine
Choosing the right dot peen marking machine is desirable for the best quality. Therefore, it is important to know some parameters associated with the process. Below are a few important parameters you must note:
Stainless Steel Hardness
Stainless steel has different grades. Therefore, they have different hardness properties. Therefore, you must ensure that the indenting pin hardness is directly proportional to stainless steel hardness.
Stainless Steel Thickness
Thickness is another property you should consider when choosing a dot peen marking tool. Encoding occurs at the stainless steel’s outermost layer. Therefore, you should control the indenting force. Controlling the indenting force depends on the type of stainless steel material and its uses. For example, if the stainless steel retains its anti-rust and anti-corrosive properties, you must reduce the indenting force such that the outermost layer is intact. However, it would be best to remember that you need a deep indentation to read the code better.
You can also ensure the highest quality of stainless steel marking by doing the following:
Use a compatible indenting pin with the stainless steel material
Always maintain the indenting pins properly.
Evaluating the Use of Dot Peen Marking With Stainless Steel
Dot peen marking is an ideal stainless steel marking process applicable in different industries. Unlike other methods, it subjects the stainless steel material to mechanical stress. However, it does not subject the material to thermal or chemical stress. Therefore, there is a guarantee of stainless steel preservation.
Advantages
The stainless steel mark is permanent and durable.
Stainless steel does not undergo thermal or chemical stress.
It has a high marking speed.
Disadvantages
It exposes the stainless steel material to mechanical stress.
Depending on the material, there can be noise pollution.
Dot Peen Marking on Stainless Steel
Some of our customers also seek deep engraving by a pin marker.
How to Choose the Right Stainless Steel Marking Method
We have already introduced the two popular and general methods of marking stainless steel. However, choosing the right stainless steel marking method involves understanding the properties of stainless steel material. Below are a few things to consider when looking for the right method.
· Stainless Steel Grade
The stainless steel grade you are working with plays a huge role in your stainless steel marking method. For example, it plays a huge role in the color obtained in laser engraving. It also plays a huge role in the indenting force and the indenting pin used in the dot peen marking system.
· Anti-Rust and Anti-Corrosive Property
Stainless steel is majorly used for its anti-rust and anti-corrosive properties. These properties occur due to the chromium layering of the stainless steel material. The chromium layer prevents rusting and corrosion of stainless steel by stopping oxygen from reaching the steel part. However, if you remove the chromium layer, oxygen can cause oxidation of the underlying steel layer. As a result, this leads to rusting that gradually destroys the material.
Due to the importance of the anti-rust properties, the stainless steel marking method must not allow stainless steel to rust after marking. Consequently, laser annealing is the most common method as it guarantees against rusting, unlike laser engraving, laser etching, and dot peening. In addition, laser annealing will only modify the material under the stainless steel, creating the marking while the protective chromium layer responsible for its anti-rust properties is intact.
· The Marking Method Itself
Understanding the marking method plays a huge role in the right stainless steel marking method you can use. For example, dot peen marking systems are noisy. Therefore, you should consider that if you are choosing them. Also, the availability of the machines needed for the process is important.
Applications of Marked Stainless Steel
HeatSign offers an expert approach in providing stainless steel engraving and marking solutions, taking into account the industry and the exact demands of the part manufacturer.
Stainless steel marking is widely used in many fields. Some of the common examples are:
Nameplates and tag necklaces for corporate and military use
Custom etching on promo articles for marketing purposes
Corporate inventory management
Data matrix codes for easy part traceability
Mark steel medical instruments
Knife blades and other kitchen utensils
Get the Best in Terms of Stainless Steel Marking
Stainless steel is an alloy with wide applications in different industries. It is lightweight, highly tensile, and has anti-rust and anti-corrosive properties. Choosing the right stainless steel marking method comes with understanding many things. For example, the different grades of stainless steel, their use, and the available marking methods.
This article discussed the two common stainless steel marking methods and how to choose the right one. For those needing the precise and error-free stainless steel marking process, Heatsign is the right service.
