Steel is one of the most commonly used metal alloys across the world with an annual production of up to 2 billion tons. There are more than 3500 different grades of this material that are used for different applications. Different steel grades have varying properties, allowing us to use them in numerous industries.
This material is primarily composed of iron and carbon. However, several other alloying elements, such as nickel, chromium, and manganese, are often added to improve its properties.
Stainless steels are extremely popular and valuable due to their longevity and durability. You can use them in multiple areas, including different mechanical equipment, automotive parts, kitchenware, and marine applications, to name a few.
Out of the many grades of stainless steel available in the market, we will be talking about the 200 series stainless steel alloys in this article.
What Is the 200 Stainless Steel Series Composed Of?
The SS 200 series is part of the austenitic class of steel. These have a Face Centered Cubic structure called austenite and are known for their corrosion resistance, high flexibility, and high-temperature resistance.
SS 200 series mainly contain chromium, nitrogen, manganese, and nickel in small amounts. Compared to other stainless steels, these have more nitrogen and less nickel.
The amount of chromium in the 200 series stainless steel is 16-18%, and the amount of manganese is 5-7%. However, the amount of nickel is relatively low, between 1-5%. 0.25% Nitrogen is also present, which provides corrosion resistance and high yield strength.
Members of the SS 200 Series
These are the grades you need to know of.
201 Grade
This grade has a lower amount of nickel and high levels of manganese, up to 7.5%. It has up to 0.25% nitrogen which provides higher strength. In mild conditions, you’ll benefit from good corrosion resistance if you’re using this material.
202 Grade
This grade is similar to 201 but has higher amounts of chromium of approximately 17-19% are present. So, unsurprisingly, it has higher corrosion resistance.
204 Grade
This grade’s composition is similar to other 200-series stainless steel grades. However, it includes copper of up to 2-4%. This increases the formability of the alloy, and you draw this steel grade in wires.
205 Grade
The 205 grade contains more manganese and nitrogen. The amount of manganese is between 14-15.5%, whereas the amount of nitrogen is between 0.32-0.4%. These steels are often hardened through the precipitation hardening process, and their properties include good corrosion resistance, high strength, and high hardness.
Properties of SS 200 Series
The 200 series stainless steels have outstanding properties that make them suitable for numerous applications.
Physical Properties
The density of the 200 series stainless steel lies in the range of 7.8-8.0 grams per cubic centimeter. These steels have high melting points from 1398°C to 1427°C.
Stability Against Corrosive Forces
The SS 200 series is stable against corrosion; however, this property is not as strong when compared to other classes of stainless steel. These materials can experience pitting corrosion in high moisture and chlorine-rich environments. Although SS 202 and 210 show slightly better corrosion resistance in such cases
High Strength
200 series stainless steel have higher strengths than other steel classes. The tensile strength varies for different grades. The 201 stainless steel has a tensile strength between 515-1035 MPa, while grade 202 has a tensile strength of about 585-758 MPa.
Impact Resistance and Toughness
These steels have excellent impact resistance and toughness. You can use the 200 series stainless steel for applications where a sudden force is applied. And they maintain their impact resistance below zero degrees, making them suitable for low-temperature applications.
Low Formability
The steels in this series show low ductility and high strength. As a result, the 200 series stainless steels are more difficult to form into different shapes. You can improve the formability of these steels if you add copper in small amounts.
Low Weldability
Generally, the 200 series stainless steels are more difficult to weld. Lower amounts of chromium in these steels can cause cold cracking in structures after forming. During welding, there is a chance that the thicker sections are difficult to weld because stress accumulation can cause cold cracking to start earlier.
Low Cost
These steels are generally cheaper than other steels due to lower amounts of nickel.
Low Magnetic Permeability
Due to their lower magnetic permeability, the 200 series stainless steels can be used in applications where interaction with magnetic fields should be minimum.
Applications of SS 200 Series
This series is used in different sectors of the industry. For instance:
Automotive Industry
Fuel tanks, suspension systems, exhaust systems, and braking systems are made extensively from 200 series stainless steel. These materials resist corrosion and high-temperature oxidation, making them suitable for all such applications. Because of their high strength, you can also use these steels for manufacturing braking and suspension systems.
Automotive body structures are also often made from 200 series stainless steel due to their higher toughness and impact resistance.
This protects the occupants of the vehicle in case of a collision, as automotive bodies made out of this steel will be able to absorb the impact energy.
Medical Equipment
MRI and CT scanners are extremely sensitive equipment made using the 200 series stainless steel due to their low magnetic permeability. The 200 series stainless steels are also used in medical devices such as pacemakers and surgical equipment due to their high strength, durability, and biocompatibility.
Water Storage Tanks
You can manufacture portable water storage tanks using 200 series stainless steel to store drinking water. These steels are extremely durable and do not have any toxic effects on the water due to their high biocompatibility.
Cookware and Kitchen Utensils
These alloys are often used to manufacture cookware and various kitchen utensils. They are corrosion-resistant and durable.
The 200 series stainless steels are non-reactive and do not leach harmful contaminants into your food, even at high temperatures. The use of this steel also provides a shiny appearance to your cookware.
Washing Machines and Dishwashers
200 series steels are also found in washing machines. You can make different parts, including the drum and agitators of the washing machine. This is because these steels can bear the high pressures inside your washing machines.
They are also not vulnerable to attack from detergent and water. Various parts of your dishwashers, including racks and tubs, are also made using these steels.
Food Packaging
Due to their corrosion resistance and high strength, the 200 series stainless steels are also used in food packaging to prevent damage during storage and transport. These packaging options include cans, boxes, and different containers.
Trolleys used to carry food items can also be made using these steels. These steels can easily withstand the moisture from food items and beverages.
Indoor Architecture
Wall panels, facades, and coverings are also made using these steels due to their shiny appearance, which provides nice aesthetics. These steels are a relatively cheaper and more durable option for this application, making it a more favorable choice if you want to redecorate.
Due to these favorable properties, the interior walls of elevators are also made using 200 series stainless steel. These steels are also very easy to clean and maintain.
Limitations of the SS 200 Series
The disadvantages of this series include:
Difficult to Weld
Extra precaution is required during the welding of 200 series stainless steel. Problems such as cracking and intergranular corrosion can occur in the welded parts. You must preheat your part and heat treat it to remove welding defects.
Low Formability
Since the 200 series stainless steels have high strength and lower flexibility, it is difficult to form them into different shapes. You are required to use high forces to form the steel. The application of large forces can cause cracking in your manufactured parts.
Hard to Source
It is difficult to find 200 series stainless steel as it is not as widely used as SS 300 alloys.
Poor Magnetic Properties
You cannot use these alloys for applications requiring strong magnetic properties.
Endnote
SS 200 series consists of austenitic steels.
\Due to their versatile properties, you can use these steels for applications in various industries. These industries include automotive, food and beverage, and medical equipment manufacturing. Because of its shiny appearance, you can also use this steel grade for applications where aesthetics are important such as elevator interiors and facades.
The 200 series stainless steels are a good choice for your industry if you require high strength, hardness, and corrosion resistance but at lower costs. However, it may be difficult to locate a manufacturer producing steel that meets your industry’s needs can be challenging. For this purpose, we suggest that you contact us because we understand steel!
