Stainless Steel Grade AISI 420 | EN 1.4028 | DIN X30Cr13

AISI 420 | EN 1.4028 | DIN X30Cr13 is used in the hardened and tempered condition in many structural and fastening products where moderate corrosion resistance is required. Due to the higher carbon content, EN 1.4028 is harder than EN 1.4021 steel.

Good corrosion resistance is achieved when the steel is in a hardened condition and the surface is finely ground or polished.

It has good corrosion properties in moderately aggressive environments that do not contain chlorides, such as soap, detergents and organic acids. It also has good resistance to atmospheric oxidation up to 600 °C. The steel is not resistant to intercrystalline corrosion during welding. Optimum corrosion resistance is achieved in the hardened condition with a polished surface. In terms of corrosion, AISI 420 shows almost the same or slightly lower corrosion resistance than EN 1.4021 steel. This is due to the higher carbon content, which leads to the removal of more chromium from its composition and the development of a more highly stressed microstructure.

Welding

This grade of stainless steel is not recommended for welding. If welding is unavoidable, the following precautions should be taken: preheating of the material to a temperature in the range of 300 to 400 °C is required, followed by quenching after welding to restore some ductility to the weld zone. Filler material is used if necessary. When using inert or shielding gas in welding, care should be taken to avoid the use of any gases containing hydrogen or nitrogen, since contamination of the weld with nitrogen or hydrogen will adversely affect the mechanical properties of the steel. Before quenching, the material should be cooled to the martensitic start, at a temperature of approximately 120 °C.

Forging

When forging, it is recommended to gradually heat the material to a temperature of about 800 °C. Then, rapidly heat it to a temperature of 1050 °C to 1100 °C. Then the forging process takes place between 1100 °C - 800 °C. Then, slowly cool it in a furnace, dry ash or similar material to facilitate slow cooling.

Processing

The machinability of this grade of stainless steel is directly related to its hardness. The machining process of AISI 420 EN 1.4028 | DIN X30Cr13 is practically no different from the machining process of other carbon steels of the same hardness. The machining parameters may vary depending on the structure/hardness of the material being processed.

Physical properties

Mechanical properties