The Ultimate Guide for Martensitic Stainless Steel

 

If you are looking for hard and strong material, then, martensitic stainless steel is your best choice.

Throughout this guide, we’ll provide all the information you need to understand this type of stainless steel. You’ll learn about its properties, composition, and applications.

Here, you’ll also find helpful tips on how to get the most out of martensitic stainless steel. Tricks as well on how to ensure it is used correctly in your projects.

So whether you’re a beginner or an experienced professional, this guide has something for everyone.

Let’s now discover why it is so popular!

What is Martensitic Stainless Steel?

Martensitic is a type of alloy steel with 10.5-18% chromium content. It is known for being highly resistant to wear and other corrosive elements. That fact makes it a top choice for use in outdoor and industrial settings.

The said material is also known for its high strength-to-weight ratio. Therefore, you can use it for any high-performance applications, like producing aircraft parts.

Martensitic stainless steel is relatively easy to work with. It can be welded, machined, and formed into many shapes.

The History of Martensitic SS

Let’s discover the beginning of martensitic stainless steel and its journey until it became a popular material today.

Year	Key Milestone in Martensitic SS History
1900s	Developed by a German scientist, Adolf Martens.
1940s	Martensitic stainless steels were used in aircraft engines, due to their high strength and rust resistance.
1950s	Then it was discovered to be useful in chemical plants, due to their resistance to acids and other chemicals.
1960s	It become widely used in the food processing and pharmaceutical industries for its corrosion resistance and cleanliness.
1970s	Used in the automotive industry for their strength and corroding resistance.
1980s	In the 1980s, become a popular material in nuclear power plants for its high corrosion resistance.
1990s	Used in medical and general engineering applications for their great strength.
2000s	The martensitic SS become increasingly popular in the kitchen and culinary industries in the 2000s. It is due to their excellent quality and cleanliness. Its popularity continues until today’s applications.

Composition

Knowledge of the material composition is important for selecting the most suitable alloy for a given application.

In order to help you, here we compiled the martensitic SS composition.

Iron	11.5%-18%
Chromium	at least 11%
Carbon	0.15-2%
Manganese	1%
Silicon	0.75%
Nickel	2-3%
Phosphorus	less than 0.04%
Molybdenum	2-3%
Sulphur	less than 0.03%

Martensitic Stainless Steel Grades

Grades 410, 420, 431, and 440 are all martensitic grades. This means that they are composed of approximately 12-13% chromium, and iron as the primary alloying element.

Learning each grade can help you better understand the properties of this material. You can also select the most suitable grade for your application.

Type 410

410 Stainless Steel is heat-treatable martensitic-grade steel. It contains about 11.5-13.5% chromium, which gives it its corroding resistance properties.

This grade is mostly used in applications that require moderate protection against corrosion and high mechanical properties. Its application includes:

• Screening and mesh
• Cutlery
• Steam and gas turbine blades and vanes
• Chemical processing equipment
• Pump parts
• Mining equipment

Type 420

420 Stainless Steel is a type of high-carbon martensitic steel. It contains at least 12% chromium and 0.15% – 0.40% carbon.  Its high carbon content provides great hardness and resistance to wear.

Grade 420 can be used to manufacture medical components such as:

• Scissors production
• Needles
• Valve parts
• Other machine parts

Type 431

Grade 431 contains 16-18% chromium. This martensitic stainless steel alloy has a high tensile strength. Plus, it is heat treatable and resistant to scaling and oxidation.

It is known for its exceptional toughness and is used in a wide range of applications, such as:

• Fasteners
• Medical implants
• Pump shafts
• Decorative applications
• Industrial equipment

Type 440

440 Stainless Steel is a high-carbon martensitic stainless steel with high chromium content. Its chromium content is around 16-18%.

It is highly corrosion-resistant and is often used in:

• High-end knives
• Marine applications
• High-end watches
• Medical instruments
• Dental implants

Characteristics of Martensitic-Type of Stainless Steel

Another important to consider is by knowing its physical and mechanical characteristics. It can help you determine if you should purchase martensitic for your application.

Physical Characteristics	Higher hardness than other stainless steel High strength and toughness Low ductility and formability Low corrosion resistance High magnetic permeability High wear and abrasion resistance Good machinability Low cost
Mechanical Characteristics	High strength Good ductility High hardness High wear resistance High corrosion resistance Good magnetic properties Good machinability Good formability Good weldability

Applications

Martensitic stainless steel is widely employed in a variety of industries, from automotive to medical.

1. Automotive: Automotive parts like exhaust systems, turbochargers, and engine components are manufactured using martensitic steel. Its high strength makes it ideal for these applications.
2. Aerospace:  In the aerospace industry, martensitic steel is used for components that require strength and corrosion-resistant properties. It is used to manufacture aircraft engines and structural components. As well as turbine blades and other aircraft components.
3. Medical: Any martensitic stainless steel grades are used in the medical industry for implants and surgical instruments. Its biocompatibility makes it ideal for these applications.
4. Marine: In the marine industry, different grades of martensitic SS are used for shipbuilding and offshore structures.
5. Architecture: The said stainless steel is used in architecture for decorative and structural applications. It is used for cladding and façades, as well as for furniture and sculptures.
6. Food Processing: It is used in the food processing industry for equipment such as food slicing and dicing blades, blenders, slicers, grinders, mixers, dough rollers, and other food processing machinery. Its high corrosion-resistant and low costs make it a popular choice among food processors.

Differentiating Ferritic Over Martensitic

Knowing the deep differences between ferritic and martensitic steels can be important for many applications. So if you’re an engineer or designer, it will help you choose the right material for specific applications.

Martensitic and ferritic steels are both kinds of stainless steel. But they do have different properties and are applications that you need to learn.

Ferritic steels are magnetic and have low carbon content, making them resistant to oxidation. They also have high tensile strength and are easy to form and weld. Martensitic steels, on the other hand, have higher carbon content and are hardenable. This type is best suited for applications that require high strength and wear resistance.

The main difference between the two steels is their composition. Ferritic is composed of mostly iron and chromium. It has small amounts of other elements as well such as molybdenum, nickel, and titanium. On the other side, martensitic steels contain more carbon. It also has other alloying elements contents such as vanadium and manganese. This higher carbon content makes martensitic harder and more wear-resistant than the ferritic type of stainless steel.

When it comes to machinability and weldability, ferritic stainless steels have an advantage over martensitic. Ferritic are easier to machine and weld. While martensitic steels are more difficult due to their higher carbon content.

Differences Between Martensitic SS VS Austenitic SS

Both types of steel are used for a variety of applications, but their properties and performance differ significantly.

	By Uses/Performance	By Properties
Martensitic Stainless Steel	Martensitic steel is typically used in applications that require high strength and wear resistance, such as cutlery, medical instruments, and turbine blades.	It comes with higher carbon content than austenitic stainless steel. That gives it a higher hardness rating and improved strength. The increased hardness also makes it more difficult to form and weld. So it is not as commonly used in applications that require complex shapes or intricate welding processes.
Austenitic Stainless Steel	Its low carbon content makes it very resistant to corrosion. That’s why it is often used in food processing and chemical industries where exposure to corrosive materials is high.	Austenitic is the most widely used type and is known for its high ductility. Plus it is easy to form and weld, making it a popular choice for applications that require complex shapes and intricate welding processes.

 

Overall, martensitic SS is stronger and more wear-resistant than austenitic stainless steel. But it is also more difficult to form and weld.

You can determine which is better depending on your application and project requirements. But rest assured both of these stainless steels have high durability.

Martensitic VS PH Steel: Which to Choose?

When it comes to choosing a steel alloy, the choice between martensitic and precipitation-hardened (PH) steel can be difficult. Both are strong and durable, yet have different benefits that need to be carefully considered.

Martensitic steel is an alloy steel that is known for its strength and toughness. Therefore you can see it is ideal for applications that require durability. It is also easy to machine and forge, making it a popular choice among manufacturers. However, martensitic is not as corrosion-resistant as other types of steel. Also, its strength can degrade over time due to air exposure and moisture.

Besides, PH steel is another type of steel alloy that is specifically designed to be resistant to corrosion and wear. It is made by adding elements such as chromium, molybdenum, and nickel to a martensitic steel base. Which then makes it tougher and more resistant to tearing. It is easier to form and shape as well than martensitic steel. Only the downside, PH steel is more expensive than martensitic and is not as strong.

When it comes to choosing between martensitic and PH steel, it is important to consider the intended application and the desired properties of the steel.

The Hardness of Martensitic SS

Martensitic stainless steel has a higher hardness than other steel. This is due to its high carbon content and the presence of hardening elements, such as molybdenum, vanadium, and nickel.

The material is often heat-treated to increase its strength and hardness. When it is exposed to high temperatures, the carbon in the steel forms martensite, which is a brittle iron form. This then makes the steel harder. The hardness of martensitic steel can be as high as 70 on the Rockwell C scale.

Its hardness is determined by its chemical composition and heat treatment. Generally, it is considered to be one of the hardest stainless steel. It is also extremely tough and can withstand high levels of impact and abrasion.

Overall, the martensitic type of stainless steel is an excellent choice for applications that require strength and hardness.

The Density

The density of martensitic stainless steel can vary depending on the composition of the alloy and the specific grade used.

Generally speaking, the denser grades tend to be stronger and more corrosion-resistant than the lighter grades. The denser grades include types 410, 420, and 440. While the lighter grades include type 416, 430, 431, and 440C.

The density of most martensitic steels lies between 7.75 and 8.0 g/cm3.

Is Martensitic Type Magnetic?

Martensitic SS are non-magnetic in their annealed state. But it becomes slightly magnetic when cold-worked. Depending on the composition of the steel, martensitic steels can be slightly magnetic or not magnetic at all.

Generally, the martensitic are magnetic but not as magnetic as ferritic stainless steels.

Conclusion

Now you finally have background knowledge on martensitic stainless steel. You also learned how important this kind of alloy is for your fabrication projects.

If you need more info or help with ordering, our services are here for you. Don’t hesitate to get in touch!