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DIN 17175
The tube must have a manufacturing method that achieves a relatively smooth inner and outer surface, so that it is possible to use either a hot rolling method or a cold rolling method. Tubes should not have unacceptable cracks, creases and folds. As long as the wall thickness of the steel pipe does not exceed the allowable dimensional deviation, and does not affect the performance of the steel pipe, it is permissible to create some uneven and shallow longitudinal scratches during the manufacturing process. Mechanical machining (such as buffing) can be used to remove the slight subsidence of the surface, but not to reduce the minimum allowable wall thickness.
Reference data for heat treatment temperature
Hot working is possible from 1100 to 80 ° °C, and the temperature can be reduced to 750 °C during processing.
In the matching-correction work of the local department, attention should be paid to the effective specification of hot work; there should be a supervisory temperature system. In the higher temperature range, ie 1100 to 900 °C, it is suitable for forging and pier thickening, about 85 °C, and the temperature can be lowered to above 75 °C during the processing.
For example, before the last process, or during the same hot working process, if the heating temperature of the workpiece is above the normalizing temperature but not more than 1000 ° C, and the deformation process is above 75 ° C, or ---- In the last process, the degree of deformation does not exceed 5% - at the end of 7 00 °C, then the normalizing of the St35.8, St45.8, 17Mn4, 19Mn5, and 15Mo3 steels is superfluous. The 13CrMo44 and 10CrMo910 only need to be tempered.
For multiple times and/or long time heat treatments at temperatures around 1000 to 1000 °C, the workpiece should be cooled to around 350 °C before the last deformation process. If the normalizing or quenching and tempering treatment is more than enough, then the temperature at which the steel is hot-worked should not exceed 1 000 °C.
Conversely, if the molding end temperature is above 10 °C, then the St35.8, St45.8, 17Mn4, 19Mn5, and 15Mo3 steels must be normalized, while the 13CrMo44 and 10CrMo910 should be tempered.
14MoV63 and X20CrMoV121 steels should be reconditioned after hot work.
Pipes made of steel according to this standard may be cold-worked, such as pipe bending, flaring, drawing and pipe cutting; for X20CrMoV121 and 14CrV63 steels, the high yield point and tensile strength shall be noted. After bending, expanding, and cold drawing with normal deformation, there is no need to supplement the heat treatment.
The tube must have a manufacturing method that achieves a relatively smooth inner and outer surface, so that it is possible to use either a hot rolling method or a cold rolling method. Tubes should not have unacceptable cracks, creases and folds. As long as the wall thickness of the steel pipe does not exceed the allowable dimensional deviation, and does not affect the performance of the steel pipe, it is permissible to create some uneven and shallow longitudinal scratches during the manufacturing process. Mechanical machining (such as buffing) can be used to remove the slight subsidence of the surface, but not to reduce the minimum allowable wall thickness.
Reference data for heat treatment temperature
Hot working is possible from 1100 to 80 ° °C, and the temperature can be reduced to 750 °C during processing.
In the matching-correction work of the local department, attention should be paid to the effective specification of hot work; there should be a supervisory temperature system. In the higher temperature range, ie 1100 to 900 °C, it is suitable for forging and pier thickening, about 85 °C, and the temperature can be lowered to above 75 °C during the processing.
For example, before the last process, or during the same hot working process, if the heating temperature of the workpiece is above the normalizing temperature but not more than 1000 ° C, and the deformation process is above 75 ° C, or ---- In the last process, the degree of deformation does not exceed 5% - at the end of 7 00 °C, then the normalizing of the St35.8, St45.8, 17Mn4, 19Mn5, and 15Mo3 steels is superfluous. The 13CrMo44 and 10CrMo910 only need to be tempered.
For multiple times and/or long time heat treatments at temperatures around 1000 to 1000 °C, the workpiece should be cooled to around 350 °C before the last deformation process. If the normalizing or quenching and tempering treatment is more than enough, then the temperature at which the steel is hot-worked should not exceed 1 000 °C.
Conversely, if the molding end temperature is above 10 °C, then the St35.8, St45.8, 17Mn4, 19Mn5, and 15Mo3 steels must be normalized, while the 13CrMo44 and 10CrMo910 should be tempered.
14MoV63 and X20CrMoV121 steels should be reconditioned after hot work.
Pipes made of steel according to this standard may be cold-worked, such as pipe bending, flaring, drawing and pipe cutting; for X20CrMoV121 and 14CrV63 steels, the high yield point and tensile strength shall be noted. After bending, expanding, and cold drawing with normal deformation, there is no need to supplement the heat treatment.
