2230M/51CrV4 is a low-alloy (chrome-vanadium) spring steel. In common with most other spring steels, the carbon content is about 0.5% and the bars in stock are therefore soft annealed in order to facilitate machining and/or cold forming. Machinability is also favoured by the fact that the steel is M-treated. Via quenching and tempering, the material can attain very high levels of strength and hardness such that it is suitable for use in other applications apart from springs.
The execution for the bars in stock is peeled. As regards chemical analysis, the steel conforms fully to the requirements for grade 51CrV4 in SS-EN 10089 and in SS-EN ISO 683 - 2. The discontinued Swedish standard for this grade is 2230. In SS-EN 10089, the soft-annealed execution is designated by the addendum “+A” after the steel name. (In SS 2230, soft annealed is indicted by the addendum “-02”).
Tempering at 450-500°C after hardening in oil results in a hardness of 44-48 HRC which is the normal level for spring applications. If higher hardness is needed, tempering can be done at a lower temperature, 200 - 250°C. Compared with silicon spring steels, 2230M/51CrV4 has quite good hardenability and reasonably high levels of strength and hardness can be attained even in relatively large diameter bars, up to 100 mm.
Welding of 2230M/51CrV4 is not to be recommended.