1.3247 High Speed Steel

Designation by standards Brand name din en aisi Better s2-10-1-8hs2-9-1-8m42 Chemical composition (in weight %) C si mn cr mo niv w others 1.10max. 0.70max. 0.404.009.50-1.101.55co: 8.00 Description Capable of very high hardness values, this is a moly type high speed tool steel. The alloy has excellent hot hardness and wear resistance and is commonly employed to machine difficult to machine materials including the superalloys. Applications Typically employed to machine the superalloys and exotic, m42 is employed in drills, hobs, taps, end mills, milling cutters, form and gear cutters, broaches and chasers. Physical properties (avarage values) at ambient temperature Density [g/cm3]: 8.01 Thermal conductivity [w/m.K]: 19.0 Coefficient of linear thermal expansion 10-6 oc-1 20-100oc20-200oc20-300oc20-400oc20-500oc20-600oc20-700oc20-800oc 9.810.811.111.611.912.212.512.6 Soft annealing Heat to 820-880oc, cool slowly in furnace. This will produce a maximum brinell hardness of 230-300. Stress relieving Stress relieving to remove machining stresses should be carried out by heating to 650oc, holding for one hour at heat, followed by air cooling. This operation is performed to reduce distortion during heat treatment. Hardening Heat up to 450-600oc, then preheat to 850oc, and to 1050oc. Harden from a temperature of 1160-1210oc followed by oil, air quenching or warm bath 550oc. Hardness after quenching is 66-68 hrc. Transformation temperatures: ac1=780oc , ac3=855oc. Tempering temperature (oc) vs. Hardness (hrc) 200oc300oc400oc500oc520oc540oc560oc580oc600oc650oc700oc 62.56161.566.568686765.5645042 Tempering diagram Click the image to enlarge the diagram.Forging Hot forming temperature: 1095-982oc. Machinability Rated at 45% of a 1% carbon steel, the alloy, in its annealed condition, can be turned, drilled, tapped, milled, broached and threaded.