Laser Hardness 1.0

Calculation of the surface hardness HRC after laser surface hardening and stress relief tempering for not alloyed and alloyed special structural steels and for not alloyed quality steels

Description:

Laser Hardness 1.0 calculates the minimum and maximum hardness obtainable for a given steel after laser surface hardening and stress relief tempering standard in oven (160°C x 2h at running, or equivalent).
The tool considers the percentages of martensitic transformation near to 100% derived from cooling from the mass of the workpiece, without the aid of refrigerant fluids.
The drop of surface hardness during the stress relief tempering is distinguished as a function of the percentage of alloying elements of the material.
Laser Hardness 1.0 evaluates the minimum and maximum C content on the product analysis.
Besides to the specific steels for surface hardening are even considered other typologies of steels that can be surface hardened for special applications.
For completeness even standards by now retired and replaced are quoted.

Conditions:

  • absence of overall surface decarburizing
  • minimum diameter or thickness of the workpiece that has to be surface hardened = 10 mm
  • optimum austenitizing heating
  • open die, drop forged or rolled materials in the quenched and tempered or normalized state
  • austenitic grain dimension = 5 according to UNI 3245 : 1987 (similar to ASTM E 112-82)
  • laser source type C02 o Nd:YAG, functioning pulsated or continuous

Usefulness:

  • choice of the steel during designing
  • inspection of the treatment during quality control

Caution:

Granit Engineering suggests a careful evaluation of the workpiece geometry and of the hardenability of the material with the aim to:

  • obtain the desired effective hardening thickness
  • limit the risk of cracking due to hardening

Usage:

  • Choose the typology of steel of interest from the below list clicking on the related standard
  • In the page related to the choice done, select the desired steel. Laser Hardness 1.0 will calculate the minimum and maximum HRC hardness obtainable after laser hardening and stress relief tempering for the selected steel
UNI 8551:1984 Special unalloyed and alloyed steel finished products, open die and drop forged, quenched and tempered or normalized, suitable for surface hardening. Qualities,requirements and tests
UNI 7847:1979 Hot rolled, unalloyed and alloyed special steel products, bars and coils, for surface hardening. Qualities, requirements and tests
UNI 7845:1978 Hot rolled, unalloyed quench and tempering special steel products, bars and coils. Qualities, requirements and tests
UNI 7874:1979 Special unalloyed and alloyed steel finished products, open die and drop forged, quenched and tempered or normalized. Qualities, requirements and tests
EN 10083-1:1998 Quenched and tempered steels - Technical delivery conditions for special steels
EN 10083-2:1998 Quenched and tempered steels - Technical delivery conditions for unalloyed quality steels
EN 10083-3:1997 Quenched and tempered steels. Technical delivery conditions for boron steels
EN ISO 683-17:2001 Heat-treated steels, alloy steels and free-cutting steels - Ball and roller bearing steels
UNI 4838:1980 Hot rolled unalloyed steel finished products, bars and wire rod, for high speed machining with removal of chips. Qualities, requirements and tests
EN 10087:2000 Free-cutting steels - Technical delivery conditions for semi-finished products, hot-rolled bars and rods
UNI 8077:1980 Hot rolled special alloyed steel products, bars and coils, for nitriding. Qualities, requirements and tests
UNI 8552:1984 Special alloyed steel finished products, open die and drop forged, for nitriding. Qualities, requirements and tests
EN 10085:2003 Nitriding steels - Technical delivery conditions
UNI 3545:1980 Hot rolled special alloyed steel finished products, bars and wire rod, for quenched and tempered springs. Qualities, requirements and tests