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Mandrel bar plays a crucial role in producing large diameter seamless pipes in modern industries. In production line, it have to bear strong and complicate stretch, compressing touching stress and high temperature cold-hot yield stress under high speed cycling. Under these circumstance, chemical components, mechanical propertied, no-metallic inclusion, grain size, microstructure, ultrasonic test, size precision, surface finish, all these factories of steel are required very strictly. Mandrel bar is made from H13(4Cr5MoSiV1),
With annual output of 15 thousand tons, its quality and service life have reached to world level of that.
Our company is capable of producing a series of mandrel, such as MPM, PQF, FQM, with the diameter of Φ80~350mm, the length of 2500-17500mm.
Equipment advantage: steel making (EBT+LF(VD)+ESR)-forging(formed by hydraulic press machine + forged by rotary forging machine)-annealing-rough machining –magnetic test-heat treatment-ultrasonic test-finish machining-chrome plating-thread phosphating.
Chemical Components of H13(4Cr5MoSiV1)
C | Si | Mn | S | P | Cr | Mo | Ni | V | H | O |
0.32~0.45 | 0.80~1.20 | 0.20~0.50 | ≤0.008 | ≤0.012 | 4.75~5.50 | 1.10~1.75 | ≤0.25 | 0.80~1.20 | ≤2PPm | ≤2PPm |
Mechanical Property
SIZE |
Tensile Strength (Mpa) |
Yield Strength (Mpa) |
Elongation (%) |
Reduction of Area (%) |
Impact Value (J) |
Hardness (HRC) |
≤200mm | 1127-1274 | ≥931 | ≥8 | ≥25 | ≥20 | 60-62 |
≥200mm | 1078-1274 | ≥882 | ≥8 | ≥25 | ≥20 | 60-62 |
mandrel bar
