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M42 Hss Heat Treatment Process: Key Steps To Optimize Performance

AISI m42 steel is a molybdenum-based multipurpose cutting tool steel and is known for its high hardness and excellent hot hardness. It also has excellent high compressive strength, fine and uniform carbide particles, good wear resistance, easy processing and other properties. In many manufacturing fields, m42 high-speed steel is widely used and is an indispensable material. However, achieving and optimizing excellent performance of m42 hss depends on its correct heat treatment process. Therefore, this article will discuss the heat treatment process of Songshun Steel for manufacturing m42 steel.

Preheating Treatment

The heat treatment process of M42 steel usually starts with full preheating. The general preheating temperature is between 730-871℃, which depends on the specific application requirements and the size of the steel. Preheating m42 hss helps reduce internal stresses and deformations and ensures even heating throughout the steel, preparing it for subsequent heating and cooling stages.


The isothermal annealing temperature of ASTM m2 tool steel is controlled between 800~880°C and maintained for a period of time, and then slowly cooled to approximately 600°C in the furnace at a rate of no more than 50°F per hour, with a hardness above HB269. The purpose of m2 hss annealing is to eliminate stress and defects within the material and improve its plasticity and toughness.


Quenching is an important step in the heat treatment of m42 hss, and it is also the process of hardening m42. The preheated m42 tool steel is heated to 1150-1210℃, salt bath furnace 1160-1180℃ or controlled atmosphere furnace 1180-1190℃, then rapidly cooled (water cooling, oil cooling or salt bath), the quenching medium depends on the size of the steel and desired hardness. Its quenching process will change the structure of the steel into a fine, uniform martensite structure, thus improving its hardness, strength and wear resistance.


Hss m42 is tempered immediately after quenching, because the quenched m42 hss is too brittle and hard, and needs to be tempered to reduce its brittleness and improve toughness. Usually the tempering temperature of m42 steel is controlled at 500-600℃. It is recommended to temper three times, with a temperature of at least 2 hours for each cycle, and to cool completely between two cycles to obtain good results. Tempering duration and temperature depend on the desired final properties, but care must be taken to control each parameter to ensure the steel achieves the ideal balance of hardness and toughness. The hardness of M42 HSS after tempering is completed is 63~69HRC.


After tempering is completed, the aisi m42 hss needs to be properly cooled. Cooling can usually be carried out gradually at room temperature to avoid additional stress and deformation, ensuring the stability of the material and maximizing its performance.

The above are the main heat treatment process flow and parameters of m42 hss carefully designed and optimized by Songshun Steel, which can maximize the excellent performance of m42. Moreover, different customers have different specific applications and final performance requirements, so targeted adjustments will be made. Therefore, through reasonable heat treatment process, the service life and performance of hss m42 manufacturing various cutting tools, tools or molds can be improved, thereby meeting the needs of various application fields.


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Dongguan Songshun Mould Steel Co., Ltd.

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