Synopsis of Process Routing: Cold drawn and bright NBK seamless steel tube is used as the tube to be phosphated.The phosphated is realized with the imported chemical fluid to form a black film.The antirust oil is absorbed by means of the micro pore on the film to prevent from the rust.The caps are covered at two ends of tube to prevent from the dust.Main Features: Bright black.Color is homogeneously distributed on the tube surface.The tube has good property of antirust.Main Application: Used in hydraulic system,nested card connector(pipe joints) with matching.Main Material & Mechanical property: The steel grades of raw material used in our company are mainly ST35, ST37.4, ST45, ST55, CK45, ST52.4, etc. produced by Shanghai Baosteel Group.The steel tube produced by KWK STEEL has excellent mechanical property and performance in process.The steel tube is able to withstand the high pressure, impact and particularly suitable for application of hydraulic machinery and automotive fabrication.The tube can be cold bent at any angle.No crack will occur after flaring and flattening for the industry,which the bending and forming is required in process.Surface Quality:The internal and external surfaces of tube must be clean without any oxidization, crack, fold, rolling fold, scar and laminar defect.The status of inner and outer surfaces is the same as that of the process and heat treatment, but the depth of defects (e.g.scratch mark, bulge and concavity) is not allowed to exceed 0.025mm(such requirement is strict than DIN2391 standard).Packing against corrosion and transportation of tube:The steel tube was painted with antirust oil, covered with caps at two ends, packed with plastic film and linen or wooden case.Note:Certificate of quality assurance of tube will be presented.
