Broken nitrided case - 1.7131

 

The component was subjected to a nitrogen hardening for the production of a surface with high wear strength. This hardening method is carried out in agents giving nitrogen (gaseous or liquid). Aim of this treatment method is a hard, wear resistant surface while the core is having a height ductility. The diffusion zone is hard and forms the ductile and supporting lower layer for the white compound layer. The basic structure serves as a load-bearing lower layer for the complete nitrided case. Many construction elements are used only at the surface on wear and need a tough core to absorb the strengths. If the pressure towards the nitrided case is too high for the strength of the basic material, she can break through. In this case the wrong material was selected. Material of this sample is 1.7131 (16MnCr5) .

Hardening test HV 1 at the microsection
ca. 0,10 mm distance of the surface :   625 HV
ca. 0,20 mm distance of the surface :   575 HV
ca. 0,30 mm distance of the surface :   510 HV
ca. 0,40 mm distance of the surface :   460 HV
ca. 0,50 mm distance of the surface :   360 HV
ca. 1,00 mm distance of the surface :   200 HV
basic structure :   160 - 170 HV

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