23rd of November ,2023

420H stainless steel's mechanical performance

Stainless steel plates are iron alloy containing iron, carbon, chromium and other trace elements. 420H steel is a alloy containing chromium and molybdenum. Its logo is SCM, and its specifications conform to the Japanese industrial standards (JIS) that manage all industrial activities in Japan. The United States Iron and Steel Association (AISI), that is, the United States is equivalent to JIS and does not classify this steel. However, the Automobile Engineer Association (SAE) rated it as SAE 4130, and its British standard (BS) level was 708H20. According to the heat treatment used in the production process, all steel has different strength and mechanical properties.

The carbon content of 420H steel is 0.17 % to 0.23 %, making it a structural steel for medium carbon. Its chromium content range is 0.85-1.25 % by weight. Its molybdenum content is 0.15-0.30 % by weight. The alloy contains trace, silicon, manganese, sulfur and copper.

The flexibility of steel depends on its carbon content. Low -carbon steel is steel with a carbon content of less than 0.15 %. They are flexible into pieces and brushed, but they are not very strong steel. High-carbon steel contains 0.5-1.5 % of carbon, which is used for casting and mechanical processing. These two steels are non -structural steel. Mid-carbon steel is called structural steel, with a carbon content of 0.12-0.24 %, for all structural activities.


Hardness is the resistance of metal to deformation, scratching and bending. The hardness test should be applied to the surface and measured the indentation generated. The hardness of steel increases with the increase of carbon content. Adding chromium to alloy can increase the hardness of steel. Mid -carbon steels such as SCM 420H need to be further hardenic through surface heat treatment before industrial applications (such as gear manufacturing).

Steel's tensile strength can measure how much it can stretch without breaking. The stretch holder holds a piece of steel between the two clamps and applies the stretch force. High -carbon steel has a high tensile strength. The performance of this material increases with the increase of the hardness of the material. The molybdenum in SCM420H increases the stretching strength of steel, so that it can be used for turbine rotor blades.

Yingli Steel's tolerance will not permanently deform, that is, its yield strength. The silicon and phosphorus content of SCM420H steel and chromium and molybdenum increase the yield strength to make it suitable for bearing structure.

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