HT250 is the grade for gray cast iron.
HT represents gray cast iron, with HT being the abbreviation for gray cast iron in Chinese Pinyin. Gray cast iron HT250 indicates the minimum tensile strength of ø30 specimen is 250MPa.
- Carbon (C): 3.16-3.30
- Silicon (Si): 1.79-1.93
- Manganese (Mn): 0.89-1.04
- Sulfur (S): 0.094-0.125
- Phosphorus (P): 0.120-0.170
- Tensile Strength (Rm): 250 MPa
- Hardness (RH=1): 209 HB
- Specimen Size: Bar Diameter: 30 mm
- Good strength, wear resistance, and heat resistance
- Excellent vibration damping
- Superior casting performance, requires artificial aging treatment
- Application Range: Suitable for pump casings, containers, tower vessels, flanges, packing box bodies and covers, carbide towers, nitration towers, etc. Also used for machining bed bodies, columns, cylinders, gears, and parts that require surface quenching.
- Due to its small thermal deformation, it is commonly used in high-temperature environments.
- Heat Treatment Specifications: (To be specified by the supplier; the provided details are for reference)
- Microstructure: Flake graphite + pearlite
HT250 can achieve HRC60 with quenching, but gray cast iron (HT200, HT250, etc.) is generally used in annealed or normalized conditions, not subjected to quenching treatment. If hardness is required in specific areas, high or medium-frequency quenching can be performed.
- Medium-Frequency Quenching: Quenching depth of 3-5 mm, hardness HRC50, minimal workpiece deformation.
- High-Frequency Quenching: Quenching depth of 1-2 mm, quenching temperature 850°C, surface hardness above HRC50; quenching temperature 900-1000°C, surface hardness can reach HRC60.
Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.
Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.
Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.
The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.
Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.
The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.
