Boiler seamless pipe (hereinafter referred to as boiler pipe) is an important material for manufacturing boilers, its quality is directly related to how the manufacturing quality of the boiler so that the quality of the installation and use of quality. This should be a quality boiler steel pipe factory to be made by the guarantee, but in short supply, to use the boiler tube boiler factory always found some quality problems, it made major boiler pressure parts such as waterwall tubes, convection tubes, superheater tubes, heat exchanger tubes leaking or burst pipes have occurred, has become plagued boiler quality of a big problem, this boiler manufacturers and users have a great comment. In the case of a seller's market, almost assumed the boiler factory including material suppliers, including full responsibility; how to control the quality of boiler tube boiler manufacturers has become increasingly concerned about the problem, the solution is nothing more than two two: one is by the root of the boiler steel pipe hydrostatic test; another is to implement a 100% boiler pipe eddy current testing.
According to materials science point of view, excellent metal materials whose chemical composition, physical properties, geometry should be continuous, pure and uniform. If these three deficiencies or destroyed, the metal material that is defective. If the metal material exists on the geometry of the discontinuity ( i.e. does not close or does not dense compactness or nature), for example, cracking, shrinkage, from the skin, pits, layered, pinholes, slag, etc., the presence of metallic materials that wounds (referred to as a wound), it does not include the chemical composition of non-continuous or discontinuous on the physical properties. From here we can see, the defect contains injuries. Boiler tube in the smelting and rolling process also may be flawed and injuries. According to the Steel Plant introduction, boiler tube defects (here mainly refers to the injury ) mainly on the surface, an inner surface and an outer surface more. About 70% of these defects from materials (billets), billets insufficient oxygen remaining in the slag inclusion, shrinkage, etc., it is likely to occur rolled steel transverse cracks, laminated, folded, heavy leather and other defects, longitudinal cracks are mostly caused by rolling strain. If the boiler tube in the emergence of these defects or injuries that the material appeared in the discontinuous density inside the material is damaged, the water pressure is likely to leak test, made of boiler pressure parts have at runtime likely to leak or burst pipe. Because of this, in order to ensure the quality boiler steel, whether or foreign country for boiler seamless standard are clearly defined, as the process performance guarantee, pipe pressure test should be made by the root.
