P20+S Steel

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Applications

Plastic moulds, large mould frames and bolsters
injection moulds
die holders AND Zinc die mould casting
shafts and wear strips

Physical Properties

Density	0.284 lb/in³ (7861 kg/m³)
Specific Gravity	7.86
Modulus of Elasticity	30 x 10⁶ psi (207 GPa)
Thermal conductivity	24 Btu/ft/hr/°F 41.5 W/m/°K
Machinability	60-65% of a 1% carbon steel

Thermal expansion 12 x 10-6/ºC, 20-100°C

Mechanical Properties

Poisson’s ratio 0.27-0.30
Izod impact unnotched 28.0 J
Elastic modulus 190-210GPa

Coefficient Of Thermal Expansion
Temperature ºF	in/inºF x10⁶	Temperature ºC	mm/mmºCx10⁶
70-200	6.7	21-93	12.0
70-500	7.2	21-260	12.9
70-1000	7.6	21-538	13.7

Typical Analysis

Carbon	0.40%	Silicon	0.40%
Manganese	1.00%	Chromium	1.20%
Molybdenum	0.35%

Forging

P20S Steel is heated slowly and forged at1050°C( not below 930°C). Then it is cooled slowly.

Annealing

P20S Steel is heated uniformly at a temperature of 710-740°C , then soaked well and cooled down slowly in furnace.

P20S Steel is heated to 460-500°C, then soaked well and cooled in air.In order to relieve machine strains,stabilizing is recommended before finishing the machining,in parts where dies have to be heavily machined.

Hardening

Uniformly P20 Steel is heated to 830-870°C and then oil quenched.

Tempering

Uniform heating and soaking at tempering temperature is needed for minimum 1hour/25mm of section. Then it is cooled in still air.

TEMPERATURE°C HARDNESS(HRC) TENSILE [N/mm²]

100 51 1730

200 50 1670

300 48 1570

400 46 1480

500 42 1330

600 36 1140

Nitriding

In order to give P20S steel a good wear resistance case(of approx. Rockwell C60 surface hardness), it can be nitrided. Corrosion resistance is increased by Nitriding.Nitriding is done in ammonia gas at 525°C with approx. 650HV surface hardness.

Temperature	Time	Approx. Depth of Case
525ºC	20 hours	0.30mm
525ºC	40 hours	0.35mm
525ºC	60 hours	0.50mm

Carburising / Case Hardening

Surface hardness achieved by the P20S tool component is 55 to 59 Rockwell C.

Flame / Induction Hardening

P20 attains 50-55HRC hardness after induction/flame hardening. Immediate tempering is required after hardening.P20 steel then needs to be air cooled.

Heat Treatment

This procedure will vary according to the shape and size of P20S tool component. Other factors like type of furnace,medium for quenching etc also matter.Rate of heating,rate of cooling and soaking time also vary according to shape and size of the steel.