Martempering

It is an intermittent hardening process performed slightly above the martensite starting point in order to reduce the risk of cracking and dimensional changes that may occur during hardening (quenching). Salt or molten lead baths, also called hot baths, are used for this heat treatment. The hot bath temperature can be between 150-300°C depending on the alloy of the material.

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Martempering enables the formation of bainitic structure together with martensite compared to classical oil hardening (quenching). Subsequent tempering is optional.

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The structure created is more flexible and has high toughness.

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In the light weapons industry, it is frequently preferred to keep dimensional changes to a minimum in parts where deformation is critical, such as barrels and slides.

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Suitable qualities,

• Heat treatable steels

  • 42CrMo4, SAE 4340​, 100Cr6

• Manufacturing steels​

  • C1040​

• Tool steels​

  • 1.2344, 1.2379​

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CQI-9 Table A is used for this heat treatment technique in the automotive industry.

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