Production Process Description:
high quality steel tube embryo – precision cold drawn – anaerobic heat treatment (NBK state) – NDT – High Pressure Oil Test – surface rust oil treatment – the dust seal two.
We select raw materials:
high quality Baosteel, Xingcheng Special Steel, Huaigang raw materials. Physical and chemical performance testing to ensure within acceptable ranges for each consignment. After detecting internal perforation, each pipe size are permitted deviation range. This ensures a higher wall thickness tolerances and concentricity.
Production process quality control:
We used to pull the domestic first-class machines, the production process through the inner and outer superhard mold control, so the product’s dimensional tolerances and ovality tolerance control at a high level. By the first, middle and end of the inspection to ensure product quality.
Inner and outer surface cleanliness:
We use the automatic washing machine cleaning the hole, rotary brush cleaning and high pressure oil and wash the outer surface of the inner hole. This new steel production process can effectively remove all the particles adhering to the hole and the surface of the steel pipe, the inner and outer surfaces of the steel pipe was very clean and bright effect.
Anti-rust oil coating the finished tube:
We use high-pressure spraying method, a precipitation with high pressure spray gun, ensure that the inner and outer surfaces of the steel pipe clean and bright.
Precision tubes for hydraulic systems, automobiles, machinery, and other precision steel pipe, finish, cleanliness, there are areas of high mechanical performance requirements.
|Standard||Steel Grade||Yield Strength min.(Mpa)||Tensile Strength min.(Mpa)||Elongation A min.(%)|
DIN2391 precision steel surface protection:
Pipes for corrosion applications. An inner surface and an outer surface with a high pressure flushing.
DIN2391 precision tube test:
Precision steel mandatory experimental chemical analysis, tensile testing, dimensional inspection and surface inspection.
Specify test: acceptance test criteria 3.1.B (3.1.A, 3.1.C).
Limited test: flattening test, flaring test, roughness and non-destructive testing to detect longitudinal defects: turbine inspection test, in accordance with EN10246-1 standard eddy current testing to prove leak test.
Precision steel warranty book:
Accordance with the standards issued by the warranty book, for example, we will show: EN10204 (-2.2 infinite qualitative test, qualified testing 3.1.B or 3.1.A, 3.1.C)
|DIN2391 standard steel and heat treatment process delivery conditions:|
|Delivery Condition||Heat Treatment Process|
|+C||Cold drawn / hard. After the final cold forming no heat treatment.|
|+LC||Cold drawn / soft. After the final heat treatment limiting deformation cold drawn, allowing a degree of cold deformation|
|+SR||Steel heat treatment is applied after the last cold deformation process, the result of state steel after due process, the residual stress deformation and machining makes a certain degree of difficulty increases.|
|+A||In the final step of the steel pipe after cold deformation, placed in a controlled atmosphere furnace for annealing.|
|+N||In the final step of the steel pipe after cold deformation, placed in a controlled atmosphere furnace at a temperature above the phase transition point to continue annealing.|
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