Waterjet cutting of stainless steel

Waterjet cutting of stainless steel is a type of technological process for processing stainless metal, in which the cutting tool, instead of cutters, is water enriched with abrasive additives, supplied under high pressure to nozzles and at high speed destroys the integrity of the metal.

This is a precise method in which material is removed by cutting with a high-pressure water jet containing abrasive particles. This versatile and effective method allows cutting corrosion-resistant alloys and stainless steel grades.

Stainless steel is a very durable and versatile material used in many industries. It offers excellent structural integrity and corrosion resistance for items ranging from home appliances to aircraft components. However, stainless steel can be challenging to work with due to its strength and rigidity. This is where waterjet cutting can help.

This cutting method uses a non-thermal approach, in which a high-speed stream of water and abrasive material gradually destroys the metal. Waterjet cutting is tens of times better than laser cutting, with a cutting depth of up to 25 cm.

Moreover, this method provides smooth and flawless edges, free from structural defects, micro abrasions or thermal damage. Waterjet cutting allows processing complex shapes and patterns thanks to the multi-axis cutting head. On the other hand, it can process both large and small parts.

How does waterjet cutting stainless steel work ?

Waterjet cutting of stainless steel is a highly efficient and versatile processing technique that is used in a variety of industries around the world.

This process of industrial erosion involves accelerating water under extreme pressure inside the selected material, resulting in precise and clean cuts. The mechanism of waterjet cutting stainless steel:

High pressure water generation

The process begins with the generation of water under very high pressure. Specialized pumps force the water. These pumps can reach pressures of up to 60,000 pounds per square inch. The water then enters the mixing chamber under high pressure.

Mixing chamber

Water under high pressure is mixed with an abrasive material, usually garnet sand, in a mixing chamber. The pressure creates a vacuum, drawing the abrasive material into the water flow. The garnet sand acts as a cutting agent and aids in the erosion process.

Nozzle and focusing tube

The mixture of water and abrasive is then forced under high pressure through a nozzle, usually made of ruby ​​or diamond. The role of the nozzle is to precisely direct the water and abrasive onto the target material. A focusing tube is often used to further concentrate the jet and achieve even greater cutting accuracy.

A high-velocity jet of water and abrasive is directed toward the stainless steel surface to be cut. When the jet makes contact, the abrasive particles destroy the material, creating a narrow cut. The speed at which the erosive process occurs makes it appear to be cutting.

What types of stainless steel can be cut with waterjet cutting ?

Different industries use different types of stainless steel. Most of them can be processed using waterjet cutting.

Waterjet cutting of precipitation hardening stainless steel

PH stainless steels have exceptional strength and durability. When machined, these alloys can provide three to four times the strength of conventional austenitic stainless steels. This makes them ideal for applications in the oil and gas, nuclear, and aerospace industries. Waterjet cutting is an effective method for cutting PH stainless steels due to their good machinability.

Waterjet cutting of duplex (ferritic-austenitic) stainless steel

It contains a mixture of austenite and delta ferrite. That is why this type of stainless steel is known as "duplex". These stainless steel alloys are superior to austenitic stainless steels in terms of tensile strength. Duplex stainless steels are often used for pipes and pressure vessels in the oil refining industry, as well as for piping systems in the oil and gas sector due to their physical properties and chemical resistance. Waterjet cutting can effectively cut duplex stainless steel.

Waterjet cutting of martensitic stainless steel

Martensitic stainless steel is the least common type of stainless steel alloy. Although they have higher toughness than ferritic or austenitic alloys, their corrosion resistance is often lower. However, for applications requiring high strength and impact resistance, martensitic stainless steel alloys are often the best choice. In cases where corrosion resistance is also required, these alloys can be combined with a polymer protective coating. Waterjet cutting can be used to cut martensitic stainless steel, especially when precise and intricate cuts are needed.

Waterjet cutting of ferritic stainless steel

Ferritic stainless steels are the second most common form of stainless steel after austenitic alloys. As the name suggests, ferritic stainless steels have magnetic properties. Cold working is a way to strengthen these alloys. Due to their lower nickel content, ferritic stainless steels often have a lower cost than other types of stainless steel. Ferritic stainless steels are suitable for waterjet cutting because the high-pressure water jet easily cuts these alloys. The cost-effectiveness of waterjet cutting makes it a good option for cutting ferritic stainless steel.

Waterjet cutting of austenitic stainless steel

These are the most commonly used types of stainless steel. Austenitic stainless steels typically have a higher concentration of chromium than other steel alloys. This high concentration of chromium increases their corrosion resistance. Austenitic stainless steel alloys are also non-magnetic. However, this property can change with cold working. Waterjet cutters can cut austenitic stainless steels, but additional precautions may be required due to their higher hardness.

Application of waterjet cutting of stainless steel

The ability of waterjet cutting to cut complex shapes and patterns makes it the best choice for many types of stainless steel cutting. Some common applications for waterjet cutting of stainless steel include:

Medicine

The healthcare industry relies heavily on the precision of waterjet cutting to meet extremely high accuracy requirements:

• Medical equipment. The medical industry makes extensive use of waterjet cutting for a variety of purposes. One of the leading applications is the production of medical devices. Waterjet cutting allows for the creation of complex shapes and patterns for these devices, from pacemakers and defibrillators to catheters. It also allows for the production of unique medical equipment designed for special use in operating rooms or intensive care units.
• Implants. This technology is also used in the production of implants, including dental, knee and hip joints. Waterjet cutting allows for the creation of complex patterns and shapes, ensuring a precise fit for patients. This personalized approach is especially useful for implants that are tailored to the patient’s anatomy.
• Surgical instruments. Waterjet cutting plays a significant role in the production of surgical instruments. This method allows for precise and complex cutting of scales, forceps and needles. It also allows for the production of customized surgical equipment for specific purposes, such as devices for minimally invasive surgery.

Marine applications

The marine industry also makes extensive use of waterjet cutting to produce stainless steel components.

• Ships and boat components. Waterjet machining is commonly used to create complex shapes and patterns for boat and ship components. Waterjet cutting is a precise method for cutting parts including valves, nozzles, and propellers.
• Decks. When it comes to decking, waterjet cutting is a popular method for cutting stainless steel. It can create complex designs and patterns for deck elements such as hatches, railings, and stairs. Waterjet cutting allows for the creation of custom decks with unique characteristics tailored to specific marine applications.
• Hulls. Waterjet cutting is a common method for cutting stainless steel hulls. It allows complex shapes and patterns to be cut directly onto hull parts such as strakers, keels and rudders. Waterjet cutting also allows for the creation of unique hulls, including curved ones with distinctive features.

Construction

Waterjet cutting plays an important role in cutting stainless steel structural elements for construction purposes.

• Structural components. Waterjet cutting technology allows beams and columns to be cut into complex shapes and patterns. This allows for the production of structural components with unique characteristics that meet the requirements of construction projects.
• Columns. Cutting stainless steel columns for construction purposes is another application of waterjet cutting. This technique allows for precise carving of patterns and decorations on bases, capitals and flutes. In addition, waterjet cutting allows for the creation of custom columns with specific characteristics, enhancing the aesthetics and functionality of buildings.
• Beams. Construction sites often use waterjet cutting to cut stainless steel beams. Ribs, flanges, and webs can be cut into complex shapes and patterns to produce reliable, accurate results. Specialty beams, including curved beams and beams with unique characteristics, can be produced using waterjet cutting.

Industrial production

Waterjet cutting is a common method in the industrial sector for cutting stainless steel for mechanical purposes.

• Machinery. Gears, shafts, and housings are examples of machine parts that can be cut into complex shapes and patterns using this technique. Waterjet cutting also allows for the production of customized components, such as a fixture.
• Home appliances. Ovens, refrigerators, and dishwashers are just a few of the appliances that can benefit from waterjet cutting. It allows you to create complex shapes and patterns for a variety of appliance parts, including handles and trim. In addition, waterjet cutting can be used to produce unique components tailored to specific appliance designs.
• Furniture fittings and jewelry. Waterjet cutting can be used to cut out intricate shapes and patterns. Waterjet cutting is also a mass production option that allows you to create unique product components, prototypes, and molds.

Advantages of waterjet cutting stainless steel

Traditional cutting methods such as spraying or plasma cutting can result in heat distortion, jagged edges and a limited range of shapes. Waterjet cutting is the ideal solution for cutting stainless steel accurately and efficiently. The benefits of waterjet cutting stainless steel include:

• Efficiency. Waterjet cutting has several advantages when it comes to cutting stainless steel. One of the main advantages is its efficiency. Unlike other cutting technologies, waterjet cutting does not require setup time or initial drilling of holes. The waterjet pierces the metal as it works, making it fast and convenient. This means that the cut component can be used immediately without any additional steps after it has been cut. Additionally, unlike other cutting methods, waterjet cutting does not require switching gas or optics when cutting different materials, making it a versatile choice.
• Versatility. This type of cutting is known for its versatility. It has no limitations in cutting along two axes, meaning it can easily cut any shape. Waterjet machines can work with a variety of materials, including aluminum, stainless steel, copper, tin, titanium, and brass. It allows you to cut stainless steel materials up to 25 mm thick, as well as thin ones. This is a significant advantage over laser cutting machines, which cannot cut some reflective materials. With waterjet cutting, you can achieve precise cuts on a variety of materials.
• No heat damage. One of the key benefits of waterjet cutting stainless steel is that it is a cold cutting method. Other cutting methods that generate heat, such as plasma cutters, lasers, and torches, can create heat affected zones. These zones are areas where the microstructure and characteristics of the metal have been altered due to the heat generated during the cutting process. Heat affected zones can have a negative impact on the strength of the metal. With waterjet cutting, there is no heat damage or heat affected zones. The lack of heat means that parts come off the cutting table in perfect shape, with smooth, crisp edges.
• High precision. Waterjet cutting offers high precision. Its ability to precisely control the angle at which the jet hits the material being cut allows for greater precision than conventional cutting methods. This means that more complex patterns can be achieved without sacrificing accuracy or speed. In fact, waterjet cutting can be four times more precise than a plasma cutter. Additionally, waterjet cutting can maintain precise tolerances, which is important for a wide range of applications.
• Environmentally friendly. Waterjet cutting is an environmentally friendly cutting method. Unlike other cutting methods, it does not produce toxic waste or fumes. This makes it a cleaner and safer option. Additionally, waterjet cutting produces less waste because the narrow kerf washes away less material during cutting. This can allow more parts to be cut from a single sheet or allow more material to be recycled, reducing overall waste.

Tips and precautions for waterjet cutting stainless steel

Waterjet cutting of stainless steel is generally safer than other cutting methods. However, it still has its own set of risks and unique safety precautions. Here are some important tips and precautions to remember when using waterjet cutting of stainless steel:

1. Protect your fingers, ears, and eyes. While it may be difficult to get your fingers into the waterjet stream, you can still get hurt by the slats that are used to hold materials while cutting. Regularly cleaning these slats is vital to prevent the growth of harmful microbes. To protect yourself, always wear protective gloves when removing or placing items on the waterjet. Wearing safety glasses and headgear is essential to protect your eyes and ears from potential harm. Waterjet machines can be surprisingly loud, and the speed at which they cut can exceed the capabilities of human hearing.
2. Learn and use motion controls correctly. Waterjet machines have impressive speed capabilities, moving large amounts of material per minute. It is important to keep your hands away from the machine while it is running. If you notice that something is not cutting the way you want, you need to stop and double-check. Rushing through a task can cause injury and potentially compromise your results.
3. Consider your workspace. Before using a waterjet cutter, make sure your workspace is suitable for the task. Make sure the equipment has appropriate safety warnings and instructions clearly posted on it. If it does not, make sure to correct the problem before continuing. Also, be aware of and follow any regulations or guidelines set by your employer. It is always a good idea to update your knowledge of these protocols regularly.

Waterjet cutting allows you to cut stainless steel easily and efficiently. It is the best choice for many industries due to its many benefits. Waterjet cutting is a great option for people who need high-quality stainless steel cutting.

You can achieve superior efficiency and quality by using waterjet cutting to cut stainless steel, whether you are working in the aerospace, automotive or architectural industries.

Frequently asked questions about waterjet cutting stainless steel

What is the maximum thickness of stainless steel that a water jet can cut ?

The water jet can cut through stainless steel up to 9 inches thick. If the thickness is greater than this, the cutting time will increase significantly. In some applications, water jet systems are modified to cut through even 18-inch steel blocks. However, in many cases, water jet cutters are used to cut 4-inch steel.

1 inch = 2.54 cm

How accurate is waterjet cutting ?

Waterjet machines typically have a cutting tolerance of 0.002 inches (0.05 mm). Some waterjet cutters can reduce this to 0.001 inches (0.025 mm) or less. This difference is so small that it is not noticeable to the naked eye.

Abrasive water jet cutting is the most popular cutting technology used today, whether it is for small scale manufacturers or large scale manufacturers.

The huge popularity of waterjet machines, especially abrasive waterjet machines, is not without reason. Waterjet cutting is widely used for cutting thin and thick stainless steel materials.