C Carbon Cr Chromium W Tungsten Mn Manganese Si Silicon V Vanadium
0.95 0.5 0.5 1.1 0.3 0.1 M238 factory specifications: hardened and tempered to 980-1080N/mm²(30-34HRC).
Characteristics of M238 steel: This steel is P20 plus 1.1% nickel, so it has excellent hardenability, uniform hardness from the surface to the center of the steel 12l14, excellent corrosion and polishing properties, and is suitable for nitriding, hard chromium plating and titanium plating.
M238 Usage: Suitable for all plastic molds, especially molds over 400 thick.
M238 metal forging: start from 1050℃ to 850℃, then return to the furnace to cool slowly.
M238 annealing: 720-740℃, heat through and keep for enough time, then cool to 600℃ with the furnace, and then cool in the air, the resulting hardness is about 240HB (the highest)
Stress relief: Heat to 600°C and keep in a protective gas furnace for about 2 hours, then cool slowly with the furnace.
M238 quenching: 840-860℃ insulation and then quenching oil, or 860-880℃ insulation and then air cooling at a slightly higher temperature and instant tempering, so the hardness is about 54HRC
M238 tempering: Tempering immediately after quenching, the time is not less than 2-2.5 hours, and then air-cooled out of the furnace Round (MM)
25.8 30.8 32.8 40.8 45.8 50.8 55.8 60.8 66.0 71.0 76.0 81.0 86.0 91.0 101.5
106.5 116.5 126.5 141.5 151.5 182.0 202.0 232.0 262.5 282.5 302.5 363.0 403.0
Square (MM) 25323540455060708090105
Flat shape (MM)
Forging: Cooling in furnace at 1050-850℃. Return to quality: Cool in furnace at 850-900°C.
Stress relief: After the heat is even, stay in the furnace for 1-2 hours to cool.
Quenching: oil 840-860℃ or air: 860-880℃. Stay for at least 10 minutes. If the thickness is more than 20mm, it will take 1/2 minute for every 1mm, so the hardness is about 54HRC.
Tempering: Stay for at least 1 hour during tempering, and 1 hour longer for every 20mm thicker than 20mm.
Annealing: heat through 720-740℃ and keep for a sufficient time, then cool to 600℃ in the furnace, and then cool in the air. The resulting hardness is about 240HB (the highest).
Link to this article：What is M238 steel? What are the detailed parameters of M238 steel?
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