Material

Stellite6 (ST6, UNS R30006)

Chemical composition

C: 0.9～1.4%;  Mn: ≤1.0%;  Si: ≤1.5%;  Cr: 27～31%;  Ni: ≤3.0%;  Mo: ≤1.5%;  W: 3.5～5.5%;  Fe: ≤3.0% ;  Co: margin.

Material properties

σb/MPa: 950~ 1150mpa,  σs/MPa: 550~ 650mpa,  hardness HRC: 38~44.

Main features

Stellite6 is one of the most commonly used cobalt-based alloys. Cobalt-based alloys have excellent high-temperature strength and good thermal fatigue resistance, wear resistance, and corrosion resistance. They can maintain stable performance in extreme environments such as strong acid, strong alkali, high temperature, and high pressure, and have better high-temperature oxidation resistance and High temperature corrosion resistance.

Application areas

It is suitable for manufacturing various parts and components that need to withstand high loads and extreme environments (such as wear resistance, corrosion resistance, high temperature resistance, impact resistance), and is widely used in petroleum, chemical industry, marine and other fields.

Parts processing requirements

The highest processing accuracy is 0.01mm, the highest smoothness is RA0.6um, and the concentricity of all outer circular surfaces is within 0.05mm.

Parts processing flow

Casting: precision casting, etc. to obtain a dense and uniform alloy structure.

Heat treatment: Carry out high-temperature solution treatment and aging treatment to adjust the structure and properties of the alloy.

Processing: Due to the high hardness, high wear resistance, thermal hardness and other characteristics of Stellite6, it is necessary to select appropriate tools and processing techniques during processing.

1.Choice of cutting tools:

For tool materials: Due to the high hardness of Stellite6 material, it is necessary to choose a tool material with sufficient hardness and wear resistance. Commonly used tool materials include high-speed steel, carbide, ceramics, etc. Among them, high-speed steel has high hardness and wear resistance and is suitable for rough machining; cemented carbide has good heat resistance and wear resistance and is suitable for finishing; ceramics have high hardness and heat resistance. It is suitable for high-temperature machining;

For tool geometric angle: the geometric angle of the tool has a great impact on the processing quality and tool life. Larger rake and relief angles can reduce cutting forces and cutting heat, but too large angles will lead to a reduction in tool strength.For the processing of Stellite6 materials, it is necessary to choose smaller rake and relief angles to ensure the strength and wear resistance of the tool;

For tool structure: The structure of the tool also has a great impact on the processing quality and tool life. A shorter blade and a narrower head can reduce cutting force and cutting heat, but a blade that is too short and a blade that is too narrow will result in reduced tool strength. For the processing of Stellite6 materials, it is necessary to choose a moderate blade and head width to ensure the strength of the tool and processing quality.

2. Processing process:

Roughing: Using larger cutting amounts and harder tool materials to cut the blank into the required basic shape and size. Due to the high hardness of Stellite6 material, high-speed steel tools with sufficient hardness and wear resistance need to be used during rough machining;

Semi-finishing: Based on rough machining, smaller cutting amounts and softer tool materials are used to process the workpiece surface to the required smoothness and precision. Semi-finishing requires the use of carbide tools with good heat resistance and wear resistance;

Finishing: On the basis of semi-finishing, smaller cutting amounts and softer tool materials are used to process the workpiece surface to the required accuracy and smoothness. Finishing requires the use of ceramic tools with higher hardness and wear resistance.

3. Polishing:

Use tools such as polishing wheels to polish the surface of the workpiece to obtain better finish and appearance. When polishing, you need to use an appropriate amount of abrasives and lubricants, and pay attention to controlling the polishing time and pressure.

Precautions for parts processing:

1. During the machining process, attention should be paid to controlling the cutting amount and tool speed to avoid excessive cutting force and heat that may cause burns on the workpiece surface or damage to the tool.

2. It is recommended to use coolant to cool the workpiece to reduce the temperature of the workpiece and the generation of cutting heat. At the same time, it can also improve the life of the tool and reduce the roughness of the workpiece surface.

3. When replacing tools, pay attention to check the wear of the tools and replace them in time to ensure processing quality and safety.