Boiler steel pipe manufacturing technology conditions

Boiler steel pipe manufacturing technology conditions

Boiler steel seamless pipe a. The method of manufacturing seamless pipes is the same, but there are strict requirements for steels used in manufacturing of tube. According to the use of high and low temperature into the the general boiler tubes and high-pressure boiler tubes two.

The mechanical properties of steel to ensure the steel is an important indicator of the end-use properties (mechanical properties), it depends on the chemical composition of the steel and heat treatment system. Steel standards, depending on the requirements of the provisions of the tensile properties (tensile strength, yield strength or yield point elongation) and hardness, toughness, user requirements, high and low temperature performance.

1 Overview

(1) manufacturing methods:

① general use of boiler tube temperature below 450 ℃ homemade pipe with 10, 20, carbon structural steel, hot-rolled tubes or cold drawn tube manufacturing.

② high pressure boiler tubes when used often at high temperature and pressure conditions, under the action of the tube in the high temperature flue gas and water vapor will occur oxidation and corrosion. Steel pipe with high rupture strength, high resistance to oxidation corrosion and good organizational stability.

(2) Use:

① General boiler tube is mainly used to manufacture water-wall tube, boiling water pipe, superheated steam pipe, superheated steam locomotive boiler tubes, big, small tobacco pipe and arch brick pipe.

② high pressure boiler tube is mainly used to make high-pressure and ultra-high pressure boiler superheater tubes, reheater tubes, windpipe, main steam pipe.

[Edit this paragraph] boiler tube uses

① General boiler tube is mainly used to manufacture water-wall tube, boiling water pipe, superheated steam pipe, superheated steam locomotive boiler tubes, big, small tobacco pipe and arch brick pipe.

② high pressure Boiler steel pipe is mainly used to make high-pressure and ultra-high pressure boiler superheater tubes, reheater tubes, windpipe, main steam pipe.

2 types

Boiler tubes withstand high temperature performance is pided into a the general boiler tubes and high-pressure boiler tubes. Whether the the general boiler tubes or high-pressure boiler tube can be pided into its purposes require different kinds of steel pipe.

Specifications and appearance quality.

(1) GB3087-2008 "low and medium pressure boiler seamless steel tubes under. Specifications of the various structures of steel tube used outside diameter 10 ~ 426mm, a total of 43 species. Wall thickness 1.5 ~ 26mm total of 29 species. But the locomotive boiler superheated steam pipe, opium pipe, smoke pipe and arch brick pipe diameter and wall thickness otherwise specified.

(2) GB5310-2008 "high-pressure boiler seamless steel pipe hot tube outer diameter of 22 ~ 530mm, wall thickness ranging from 20 ~ 70mm. Cold drawn (cold) tube diameter 10 ~ 108mm, wall thickness ranging from 2.0 ~ 13.0mm.

(3) GB3087-2008 low and medium pressure boiler seamless steel tubes for high pressure boiler seamless steel pipe "and GB5310-95" ". Appearance quality: Steel pipe internal and external surface allowed cracks, folding, rolling fold scarring, separation and hairline. These defects should be completely removed. Clear the depth shall not exceed the nominal wall thickness of the negative deviation, its clean-up at the actual wall thickness not less than the minimum allowed by the wall thickness.

The chemical composition test

(1) GB3087-2008 "low and medium pressure boiler seamless steel tubes under. The test method according to the chemical composition of GB222-84 GB223 steel and alloy chemical analysis method "in the relevant part.

(2) GB5310-2008 "high-pressure boiler seamless steel tubes under. Chemical composition test methods according to GB222-84 steel and alloy chemical analysis method ", the relevant part of the GB223 steel and alloy chemical analysis method.

(3) imports of the chemical composition of the boiler tube inspection relevant standards specified in the contract.

5. Boiler tube steel No.

(1) high-quality carbon structural steel No. 20G, 20MnG, 25MnG.

(2) alloy structural steel No. 15MoG, 20MoG 12CrMoG 15CrMoG 12Cr2MoG 12CrMoVG 12Cr3MoVSiTiB.

(3) rust heat-resistant steel commonly used 1Cr18Ni9 1Cr18Ni11Nb boiler tubes in addition to ensure the chemical composition and mechanical properties, by root to do hydrostatic testing to make flaring, flattening test. Steel with heat treatment delivery.

In addition, also have certain requirements for finished steel microstructure, grain size, decarburization layer.

上一篇：The undersea line pipe inspection

下一篇：Advantages and disadvantages of hot-rolled steel pipe