P20 718 1.2311 1.8519/31crmov9 Tool Mold Steel Flat Round Bar

• Type: Round
• Standard: AISI, ASTM, DIN, JIS, GB, BS
• Composition: Stainless Steel Scrap
• Technique: Forged
• Shape: Plate
• Surface Treatment: Black or as Required
• Model NO.: Round bar
• Special Use: High-strength Steel Plate, Wear Resistant Steel, Silicon Steel, Cold Heading Steel, Free Cutting Steel, Mold Steel
• Application: Tool Steel Bar
• Transport Package: Wooden
• Specification: 6-400mm
• Trademark: Smooth
• Origin: China
• HS Code: 7214100000
• Production Capacity: 5000 Ton/Year

Product Description

About products
31CrMoV9 is a nitriding steel which has at least 2.3%Cr,0.15%Mo,0.1%V as strengthening alloy elements.
Due to its high wear resistance,it is mainly used in the automotive industry and general components mechanical engineering.
30CrMoV9 is difficult to weld and therefore should not be used in weld constructions.It can attain surface hardness of 800 HV
after nitriding.31CrMov9 is directly involved the nitriding steel 30CrMoV9 (DIN1.7707).

 

Chemical Composition(%)

C	Mn	P	S	Si	V	Cr	Mo
0.27-0.34	0.40-0.70	≤ 0.025	≤ 0.035	≤ 0.4	0.1-0.2	2.3-2.7	0.15-0.25

Physical Property
Density ,g/cm3: 7.85
Specific heat capacity, J/(kg.K):460
Thermal conductivity ,W/(m.K):42
Electric resistivity,Ohm.mm2 /m:0.19
Modulus of elasticity ,Gpa: 210
Mechanical Property

Diameter d mm	16-40	40-100	100-160	160-250
Yield Strength Mpa	≥900	≥800	≥700	≥650
Tensile Strength Mpa	1100-1300	1000-1200	900-1100	850-1050
Elongation, %	≥9	≥10	≥11	≥12
impact,J	≥25	≥30	≥35	≥40
Hardness,HB	331-380	298-359	271-331	253-319

Forging
Heat the temperature between 1050ºC-1150ºC,hold suitable time for the steel to be thoroughly heated.Reheat the steel once
temperature  below 850°C. Crack is easily occured when improper cooling way after forged,so it  should be cooled as slowly
as possible in the furnace or in sand after forged.
Heat Treatment
Soft Annealing
Heat to 650-720ºC, cool slowly in the furnace. This will produce a maximum Brinell hardness of 248.
Hardening
Harden from a temperature of 870-930ºC, followed by oil/polymer or water quenching.
Tempering
Tempering temperature: 580-700ºC.
Nitriding
Gas/plasma nitriding temperature (gas, salt bath): 570-580ºC
Gas/plasma nitriding temperature (powder, plasma): 580ºC
Surface hardness after nitriding: 800 HV

Hold time,h	Hardness,HV
30	750	540	430	410	400	380	380
90	830	750	640	530	430	410	410
120	790	730	660	600	540	460	400
180	800	760	700	640	580	550	420
Depth,mm	0.15	0.25	0.35	0.45	0.55	0.65	1

Application
31CrMoV9 nitriding steel is used in mechanics automotive and general mechanics, which must be nitrided for very high wear forces,
for example, gears, rods or axes.Structural parts of medium and large cross sections and high surface hardness, e.g., valve and
gate valves, cylinders for combustion engines, superheated steam valves and fittings.