(1) manufacturing method:
(1) general boiler tube temperature under 350 , the domestic pipe mainly use 10, 20 carbon steel hot rolled or cold drawn tube manufacture.
(2) high pressure boiler tubes are often in high temperature and high pressure conditions, when using the pipe under the action of high temperature flue gas and water vapor, oxidation and corrosion will happen. Requirements of steel pipe with high rupture strength, high oxidation corrosion resistance, and have good organizational stability.
(1) general boiler tube is mainly used to produce water wall tube, water pipe, superheated steam tube, locomotive boiler superheated steam pipe, large and small pipe and tube arch brick, etc.
(2) high pressure boiler tube is mainly used to manufacture high-pressure and ultrahigh-pressure boiler superheater tubes, reheater tube, airway, such as main steam pipe.
(2) GB5310-2008 “high pressure boiler seamless steel tube” regulation. Chemical composition test method by GB222-84 and the steel and alloy chemical analysis method, GB223 iron and alloy chemical analysis method “in the relevant section.
(3) the chemical composition of imported boiler steel pipe inspection on this standard stipulated in the contract.
Boiler tube adopts steel grade
(1) the high quality carbon structural steel grade 20 g, MNG, 20 MNG.
(2) 15 mog, alloy structural steel steel grade 20 crmog mog, 12, 15 crmog, 12 cr2mog, 12 crmovg, 12 cr3movsitib, etc.
(3) heat resistant steel rust common cr18ni9, 1 cr18ni11nb boiler tube in addition to guarantee the chemical composition and mechanical properties, by the root do water pressure test, flaring, flattening test. Steel tube to heat treatment state delivery.
In addition, the microstructure and grain size of finished steel pipe, the decarburization layer also has certain requirements.
The physical properties of boiler tube inspection
(1) GB3087-2008 “low medium pressure boiler seamless steel tube” regulation. Tensile test according to GB/T228-87, hydrostatic test according to GB/T241-90, flattening test according to GB/T246-97, flaring test according to GB/T242-97, cold bending test according to GB244-97.
(2) GB5310-2008 “high pressure boiler seamless steel tube” regulation. Hydrostatic test and flattening test and tensile test, the same GB3087-82; Impact test press GB229-94, flaring test according to GB/T242-97, grain size test according to YB/T5148-93; Decarburization layer microstructure inspection by GB13298-91, inspection by GB224-87, ultrasonic inspection according to GB/T5777-96.
(3) the import and the physical properties of the boiler tube inspection and indicators relevant standards stipulated in the contract.
Boiler tube is mainly import and export situation
(1) boiler tube major importing countries are Japan, Germany. Often import the specifications of the 15914.2 mm; 2734.0 mm; 219.110.0 mm; 41975 mm; 406.460 mm, etc. Minimum specification is 31.84.5 mm, length is usually 5 ~ 8 m.
(2) in the case of the imported claim, Germany mannesmann seamless boiler tube, pipe mill imported ST45 by ultrasonic testing of census, found that a small number of internal defects of steel pipe more than the factory regulations and German steel association standards. youtube mp4