EN40B is a chromium-molybdenum nitriding steel usually supplied in the hardened and tempered condition, which offers high wear resistance together with good toughness and ductility. It is characterised by its suitability for nitriding, which can give a hard wear resistant core in the range of61-65Rc. The relatively low temperature of the nitriding process produces components with a scale free surface, and minimum distortion.
TYPICAL ANALYSIS
C.
Si.
Mn.
Cr.
Mo.
0.25%
0.30%
0.60%
3.25%
0.55%
Hardening: Heat uniformly to 880/910°C, soak until heated through. Quench in oil.
Tempering: Heat uniformly and thoroughly at the selected tempering temperature, between 570°C to 700°C.