ALTA A2 Tool Steel Properties (1.2363, X100CrMoV5)

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Cold work tool steel

ALTA A2 Tool Steel Specification

Steel properties

AALTA A2 tool steel is an air-quenching tool steel (equivalent DIN material 1.2363, X100CrMoV5) with deep air-quenching hardening performance, which is extremely beneficial for complex molds that must maintain their shape after quenching and tempering. The deformation of this steel due to air quenching is only about 1/4 of that of manganese type tool steel in oil-quenching. Its wear resistance is between manganese type and high-carbon high-chromium type tool steel like D2/1.2379, D3/1.2080, D6/1.2436, and its toughness is better than any of them. It is particularly suitable for tools that require good wear resistance and particularly good toughness.

Applications

Suitable to manufacture cold work molds require both good toughness and high wear resistance.

² Precision blanking dies for wire cutting processing and stamping dies for various purposes

² Dies for cold forging, deep drawing and wire rolling

² High-speed blanking punch, stainless steel plate punch

² Stretching dies, crimping dies, embossing dies, abrasive plastic forming dies

² Machine knives, cutting tools, rolls

Chemical composition

Chemical Composition per %

	C	Si	Mn	P	S	Cr	Mo	V	Ni	Cu
Min.	0.95	0.10	0.40			5.00	1.10	0.25
Max.	1.05	0.40	0.80	0.030	0.030	5.10	1.20	0.35	0.25	0.25

Basic melting process :

IM/EAF + LF + VD + (ESR)

Hardness :	Max 235 HB (annealed)
Reduction ratio :	5 : 1 minimum or required
Grain size :	≥ 6.0 per ASTM E112
Non-metallic inclusion :	≤ 1.0 (thick), ≤ 1.5 (thin) per ASTM E45 method A (more pure by ESR route)
Ultrasonic Test	SEP1921, EN 10308, ASTM A388 or agreed methods
Macro-structure	As per ASTM E381
Straightness / flatness	≤ 1.5 mm / m (machined), ≤ 2.5 mm / m (black)
Tolerance	Per discussed
Size range (round bars)	Ø 12 - 500 mm
Size range (flats, plates)	8 - 400 mm in thickness max. 1100 mm in width

Heat treatment

Annealing	Temperature(°C)	Hardness
Annealing	800 - 850	max. 235 HB

Hot-forming	Temperature(°C)
	850 - 1050

Hardening and tempering	Quenching temperature(°C)	Quenching medium	Frequently-used tempering temperature(°C)
Hardening and tempering	930 - 970	Oil or air-cooled	180 - 520

Ac1	Accm	Ar1	Arcm	Ms
785	835	705	750	180

Tempering structure changes by temperature:

Tempering temperature °C	Structures
200	Tempered martensite + some retained quenched martensite + retained austenite
500	Tempered martensite + small amount of austenite
600	Tempered troostite + retained austenite

** As the tempering temperature increases, the content of tempered martensite in the structure increases and the content of retained austenite decreases.

The tempering hardness of A2/1.2363 tool steel is not the only factor that determines its wear resitance. The wear rate of material increased by the increases of friction speed and loading loads.

Although the hardness of A2/1.2363 steel tempered at 200℃ is very high, but its wear resistance is not good enough. This material wear resistance is very sensitive to loading loads and friction speed.

Under the using condition of high stress and high speed wear conditions, A2/1.2363 material have better wear resistance at 500℃ tempering, which the wear mechanism is the combined effect of abrasive wear and adhesive wear.

Commonly used heat treatment specifications:

	Quenching °C	Tempering °C	Hardness - HRC
Primary hardening	950±10	200	60 ~ 64
Secondary hardening	980~1100	510~520	57 ~ 60

Vacuum quenching specifications:

Pre-heating	Second-heating	Quenching	Cooling medium	Tempering	Hardness - HRC
500~550	800~820	970~1000	Oil or nitrogen	160~200	60~62

** vacuum degree 0.1Pa when pre & secondary heating

** vacuum degree 1~10Pa when quenching

Specification for gas nitriding and gas nitrocarburizing:

Requirements		Nitriding temperature °C	Proportional gas	Applications
Hardness(HV)	Depth (mm)	Nitriding temperature °C	Proportional gas	Applications
>1000	0.03~0.05	510	Ammonia 40%, carrier gas(RX) 60%. Ammonia decomposition rate 30~40%. Insulation time 3h	cold heading dies, cold extrusion dies and punching dies .. etc.
>1000	0.05~0.07	510	Ammonia 40%, carrier gas(RX) 60%. Ammonia decomposition rate 30~40%. Insulation time 6h	Drawing die, bending die, clay die..etc.