M42 High Speed Tool Steel Bar

PRODUCT NAME : High speed tool steel bar ( forged / rolled )
STANDARD:GB/T9943-2008 GB/T9942-2008 ISO4957
GRADE COMPARISION:

 ULTRASONIC STANDARD:

GB/T6402-2008 / SEP921-84. ASTM A388
HEAT TREATMENT SPECIFICATION AND MECHANICAL PROPERTIES:

Annealing temperature:860-880℃,keep this temperature by 2-4 hours,then cooling to 600℃ in the speed of 20-30℃/h if after cold drawn precess,suggest add stress relieving annealing process Under the temperature of 600-700℃,keep this temperature by 2 houres.

Quenching & Tempering(salt bath)

Quenching:

Pre-heating in two steps:

Heating temperature under :400-500℃ and 850-900℃

Austenitizing temperature :1170-1190℃

Heating coefficient 10-15sec/mm ,quenching under 580-620℃,then cooling to room temperature.

Tempering:

Tempering temperature under :530-560℃,temperature 3 times, each time 1hour ,then cooling to room temperature.

Note:

1.Cutting tools in simple shape which requires high hardness,suggest adopt 1190-1200℃ as quenching temperature,530-540℃ as tempering temperture resulted in HRC 67-69.

2 .Cutting Tools in complex shape (such as milling cutter,tap)suggest adopt 1170-1190℃ as quenching temperature.550-560℃ as tempering temperature,resulted in HRC 66.5-67.5.(with Good toughness)

3 .Straightening under 200-450℃ after Quenching.

Chemical composition :

MANUFACTURING TECHNIQUE:
intermediate frequency furnace+ESR+ forged/ rolled
DELIVERY CONDITION :ANNEALED
SURFACE : BLACK / GRINDING / PEELING
DIMENSION : mm
Forged round bar :dia 80-250mm
Rolled round bar :dia 16-80mm
Coild rod : dia 6.5-16mm
Wire : dia 2.2-14mm
Rolled flat bar :thickness 5-90× width 44-300mm
Forged flat bar:thickness 120-800×width 120-800
length : forged bar free length 3-5.8M,rolled bar 5.8M. for customers special requirment, the bar length can do 20 meters long.
Tolerance on diameter of forged bar : black surface -0/+5mm, peeled surface -0/+3mm.
REMARK:
Above listed parameters and sepcification only for reference . Specific parameters according to standard. Requirments beyond standard will be negotiate by both sides .
Delivery state:normalized ,annealed, spheroidal annealed, quenched & tempered ,bright bar, cold-drawn, etc. Should be indicated in contract .
Listed specifications are only typical grades; products of required specifications can be developed/produced per international, Chinese or industry standards, or based on agreements with customers.
Packing :
Forged bar , rolled bar and coil packing in loose . Rolled wire packing in plastic woven cloth or wooden case.
APPLIED RANGE:

This kind steel is suitable for tools subject to server mechanical wear particularly suitable for die sinking cutters,milling cutters and components tool bits in automatic lathes.Also suitable for non-cutting shaping.

Characteristic:It is one of the typical sperhard Co hss ,with high hardness and hot hardness,high red hardness and good grindability.