A prehardened mold steel (300 HB/32 HRC) with improved machinability

W1.2312 is a chromium – manganese – molybdenum grade designed for plastic mold industry. This grade is normaly delivered in a prehardened condition at a hardness level of 300HB/32HRC. The grade has a fully homogeneous martensite – bainite microstructure. W1.2312 grade has specific sulfur addition (0.060% typical) in order to increase strongly its machinability. Compared to W1.2311 grade, 30% increase in milling speed and 300% increase in drilling speed can be expected. At constant cutting speed, tool life is multiplied a least by 5 when replacing W1.2311 by W1.2312 grade. W1.2312 is not suitable for polishing requirements.

Standard
• AFNOR: 40 CMD8S
• DIN: 40 CrMnMoS 8.6
• WERKSTOFF Nb: 1.2312
• AISI: ≈ P20 + S

Chemical Analysis
Typical values (weight%)

C	S	P max	Si	Mn	Cr	Mo
0.4	0.060	0.012	0.3	1.5	1.9	0.2

Mechanical Properties
Typical values for plates air quenched and tempered for 300 HB (thickness 45 mm – 1.8”).

	Hardness	YS 0.2		UTS		Elongation	Reduction of area	Elastic modulus
	HB	MPa	ksi	MPa	ksi	%	Z%	GPa	ksi
Longitudinal direction	300	850	123	1270	184	10	45	205	29745
Longitudinal direction	300	820	119	990	144	9	40	205	29745

Delivery Conditions
Typical delivery sizes

Thickness	Width
20 – 120 mm (.79″ – 4.7″)	1500 – 2500 mm (59 – 98.4″)
120 – 600 mm (4.7″ – 23.6″)	1500 – 2100 mm (49″ – 82.7″)

PDF: http://www.industeel.info/wp-content/uploads/2016/01/DS-MOLD-W12312.pdf