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Chemical composition of M42 high speed steel

This grade is a cobalt-molybdenum high-speed steel with high hardness and excellent hot hardness. Excellent cutting performance can be achieved with tools made from M42 HSS. With a high heat treatable hardness of up to 70, M42 HSS also has excellent wear resistance. M42 steel ( W2Mo9Cr4VCo8 ) is a high cobalt toughness high-speed steel, mainly used for high toughness precision wear-resistant hardware Cold punching die, can also be used for cutting tools and knives in the cooling.

Related Specifications

AISI ASTM A681 DIN 17350 BS EN ISO 4957

Applications

M42 high speed steel can be used in conditions where hot hardness is important. It is commonly used for cutting tools including twist drills, taps, broaches, milling cutters, reamers, end mills, band saw blades, and cold work tools.

Typical Analysis

Carbon 1.05% Silicon 0.35%

Tungsten 1.50% Chromium 3.75%

Vanadium 1.15% Molybdenum 9.50%

Cobalt 8.00%

Forging

Slowly and evenly preheat the M42 high speed steel to 650-760°C and equalize. Then increase more rapidly to a forging temperature of 1010-1150°C and equalize before forging. Do not allow the forging temperature to drop below 980°C. If this happens, reheating will be necessary. Always cool HSS very slowly after forging.

Annealing

After hot working and before rehardening, it is recommended to anneal M42. heat M42 HSS to 850°C at a rate not exceeding 220°C per hour. always maintain the temperature for one hour per 25 mm of thickness (zui minimum two hours). Cool the furnace slowly. The M42 annealed hardness achieved should be 269 Brinell or less.

STRESS RELIEF

If tools produced with M42 HSS are heavily machined or ground, stress relieving after machining and before hardening is recommended to minimize the possibility of distortion. The components are heated to 600-650°C and fully immersed (about 2 hours) and cooled slowly in the furnace.M42 tools can be finish machined prior to heat treatment.

Hardening

In a vacuum, wait for zui results to strengthen the M42 or control furnace, or a properly corrected salt bath. Before thorough the steel is heated to 820 - 870°C and then transferred to a high temperature salt bath. The exact hardening temperature to be used for M42 will depend on the type of work to be received, but generally components should be hardened at 1160 - 1180°C in salt, or 1180 - 1190°C in atmospheric or vacuum furnaces. After a brief period of holding the hardening temperature, the hardened component is not further immersed in salt at 540 - 595°C or hot oil. If the quench is allowed to bring the component to the salt bath temperature then complete the quench in still air.

Tempering

M42 tool steel components can be tempered between 510 - 595°C. The components require the lowest tempering temperature. Components require a zui low tempering temperature of 540°C, and it is recommended that hardening stresses be properly mitigated. Three tempering cycles are recommended, each at a temperature of at least 2 hours. Between tempering treatments, the component should be cooled to room temperature in still air.

Temperature [°C] 500 550 600

Hardness [HRc] 67 69 63

Heat Treatment

Heat treatment temperatures, including heating rate, cooling rate, and soak time, will vary due to factors such as the shape and size of each M42 steel component. Other considerations during heat treatment include furnace type, quenching media and workpiece transfer facilities.

High-speed steel M42 steel is widely used in metal manufacturing and cutting tool manufacturing because of its superior red-hardness compared to more traditional high-speed steels due to higher cutting speeds or increased time between tool changes. HSS M42 tool steel is also less prone to chipping when used for interrupted cuts and is less costly than the same tools made from carbide. Tools made from cobalt-containing high-speed steel can often be recognized by the letters HSS-Co.

AISI M42 tool steel is a conventionally manufactured cobalt-alloyed high-speed steel. The various stages of the manufacturing process are selected and controlled in order to obtain a final product with good structure in terms of carbide size and distribution. This is a distinct advantage for finished tools.

M42 HSS is characterized by

All-round suitability

Good machinability

Great performances

Good hot hardness

Good wear resistance

Chemical composition of AISI M42 tool steel Properties Comparison

Comparative properties of AISI M42 tool steel HSS Mechanical Properties

The steel has better process utility than M2Al, and better hot and cold workability. The hardness after quenching and tempering is the same as that of M35 steel, which is (66±1) HRC.This steel has high wear resistance, high pressure resistance and sintering resistance.M42 is supplied with annealed hardness ≤269HBW, cold drawn hardness ≤285HBW, and annealed hardness ≤277HBW after cold drawing.

Applications

It is suitable for making a variety of abrasion-resistant and impact-resistant tools for powerful cutting;<

Used in the production of a variety of high hardness and ultra-high hardness saw blades, drills, taps, broaches, hobbing cutters and a variety of milling cutters;

Used in punching molds, screw molds, and the need for toughness and complex shapes of punches and so on.

Used in cold forging molds and deep-drawing molds, etc.

Recommended for use in the cold stamping products industry, such as case factories and screw factories.