What is grade 430 Stainless steel?

Grade 430 stainless steel is by far the most popular of all straight chromium stainless steels which combines good heat and oxidation resistance up to 1500°F (816°C) and good corrosion resistance with good mechanical properties.

Grades and classifications

Grade 430 is also known as ‘steel type 1.4016’, UNS S43000 and ‘17 chrome stainless’. The latter is due to the fact that it contains approximately 17 percent chromium. It is the general purpose alloy of the ferritic class; ferritic and martensitic stainless grades ('400' series) are generally free from austenite, have high permeabilities and will attract a magnet. As such, they are classed as ferromagnetic.

Magnetism

There is a myth in the metals industry that stainless steel is not magnetic. However, magnetism and corrosion resistance are not connected. Ferritic stainless steel such as grade 430 owes its magnetism to its high concentration of iron and its fundamental structure. It can be magnetised in an electric field and so can be used for electric solenoid cores, where good corrosion resistance is also required.

Purposes

As it is a non-hardenable plain chromium stainless steel with an excellent finish quality, steel type 430 is one of the most commonly used ‘non-hardenable’ ferritic stainless steels. It is ductile and can be formed using a variety of mild stretch bending operations, roll forming as well as the more common bending and drawing processes. Common consumer product applications of this grade include automotive trim, dishwashers, furnace combustion chambers, gas burners on heating units, gutters and downspouts, range hoods and steam iron bases. Commercial and industrial applications range from nitric acid plant equipment, interior architectural applications, oil refinery equipment, roofing and sidings and restaurant equipment.

 

Chemical resistance

Grade 430 also has excellent corrosion resistance to a large variety of media including nitric acid and some organic acids, which makes it ideally suited to use in chemical applications. Its ability to resist nitric acid attack also allows its use in specific chemical applications.

Hardening

As with other ferritic grades of steel, 430’s resistance to stress corrosion cracking is very high. Type 430 stainless steel also cannot be hardened by heat treatment. Annealing is performed by heating to 815°C, soaking for 30 minutes per 25mm of thickness, furnace cooling to 600°C, followed by quickly air-cooling. The metal will become brittle if slow cooled from 540-400°C.

 

Applications

Typical applications for grade 430 stainless include:

Chemical plant equipment

Refrigerator cabinet panels

Automotive trim

Sinks

 

• Linings for dish washers

• Lashing Wire

• Vending machine components

• Oil refinery equipment

• Element Supports

• Stove trim rings

• Fasteners

• Chimney Liners

• Grade 430 v 304

• Grade 430 stainless steel is a cheaper form of stainless steel, containing just chromium. Grade 304, containing both chromium and nickel, and is more corrosion resistant, but also more expensive. Type 304 steel is also easier to form and weld than 430 stainless steel.