Metallographic diagram of SUH600 (1Cr11MoV1120°C quenched, 680°C tempered)

SUH600 is an air-hardening martensitic chromium steel, suitable for hardening in oil and by conventional methods. It has excellent overall wear resistance and impact toughness. It is widely used in the automotive and consumer product industries, particularly in components requiring superior fatigue and corrosion resistance.

The properties of SUH600 are derived from its composition of carbon, chromium, and molybdenum in the alloy. The addition of chromium and molybdenum allows the steel to have good hardenability, as well as corrosion and wear resistance. The steel also benefits from its relatively low carbon content, which increases its impact strength and makes it easier to machine and weld.

This alloy can typically be heat-treated to the Rockwell C Hardness scale (RC), with austenitization typically carried out at temperatures up to 1120 °C. The steeld is then quenched in oil or air to achieve the desired hardness. SUH600 also responds well to tempering at temperatures of about 680 °C, which increases its overall toughness and ductility.

The microstructure of SUH600 is mainly composed of ferrite and martensite. A typical microstructure of this alloy, after heat treatment, is illustrated in Figure 1. It shows that the maximum grain size is highly dependent on the cooling rate used during hardening. Faster cooling rates, or higher quenching temperatures, typically yield a finer grain structure, improved hardness and wear resistance.

The macrostructure of SUH600 typically consists of a tempered martensite microstructure, with an average grain size of 3 to 6 μm. This is caused by the relatively low carbon content and air hardening of the alloy, making it suitable for applications that require wear resistance and corrosion resistance. Figure 2 shows the macrostructure of this alloy after heat treatment and tempering.

In summary, SUH600 is an airHardening martensitic chromium steel with excellent overall wear resistance and impact toughness. It has a relatively low carbon content, making it easier to machine and weld. It responds well to hardening in oil and by conventional methods, with austenitization typically carried out at temperatures up to 1120 °C. The resulting macrostructure is a tempered martensite microstructure, with an average grain size of 3 to 6 μm. This alloy is typically heat-treated to a Rockwell C Hardness scale, with lower quenching temperatures yielding finer grains and improved hardness and wear resistance.

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SUH600 is a kind of heat resistant steel containing high chromium and molybdenum which is usually used for components with special requirements. This type of steel will be heat treated at 1120℃ and then released quenching. The following hardening process of 680℃ will make its strength and hardness get the best performance.

Metallographic structure of SUH600 is a mixture of martensite matrix and fine carbide. The steel contains about 0.07-0.1% Carbon and 12-14% Chromium. The section of steel appears with white Martensite and black tempered part. The tempered part is mainly composed of Tempered Sorbite, sub-spherical carbon and some low melting point element oxides. The range of Cementite is 0.3-0.5 μm while that of Tempered Sorbite is 2-3 μm.

The oxygen, silicon and nitrogen content in SUH600 heat resistant steel are very important. The oxygen composition should be less than 0.004%. Silicon should be in the range of 0.10-0.20 % and nitrogen should not exceed 0.028%.

In summary, SUH600 is a heat resistant steel type with very high chromium and molybdenum content. It has excellent fatigue resistance, oxidation resistance and corrosion resistance. Its hardening process is 1120℃ quenching and 680℃ tempering. Its metallographic structure is a mixture of martensite matrix and fine carbide. The oxygen, silicon and nitrogen content are very important for the mechanical properties.