CN1195100C

CN1195100C - Method for making steel pipe with ceramic lining

Info

Publication number: CN1195100C
Application number: CNB011392274A
Authority: CN
Inventors: 曹国京
Original assignee: Shanghai Meishan Baosteel Group Co Ltd
Current assignee: Shanghai Meishan Baosteel Group Co Ltd
Priority date: 2001-12-26
Filing date: 2001-12-26
Publication date: 2005-03-30
Anticipated expiration: 2021-12-26
Also published as: CN1428459A

Abstract

The present invention relates to a new technical field of a steel surface coating, particularly to a manufacturing method for a steel pipe with an inner corrosion resistance ceramic lining of wear resistance. The present invention solves the problems of high manufacturing cost of a steel pipe with a ceramic inner lining, and unstable quality of a ceramic surface layer. The present invention has a technical scheme that a manufacturing method of a steel pipe with a ceramic inner lining uses raw materials of Al and SiO2; the manufacturing method comprises the following steps of material baking, material preparing, material mixing, material charging, and ignition and sintering. The present invention is characterized in that acid residue materials (generated by ore dressing), Al and SiO2 are baked and uniformly mixed; after ignition, the acid residue materials (generated by ore dressing), Al and SiO2 react and are sintered under the action of centrifugal force, and a compact ceramic coating is formed at the inner wall of the steel pipe. The present invention can be widely used for conveying power, slurry and tailings of metallurgy industry, mine industry, electric power industry, coal industry, etc.

Description

Method for manufacturing ceramic lining steel pipe

(I) technical field

The invention relates to the new technical field of steel surface coatings, in particular to a method for manufacturing a ceramic lining steel pipe with corrosion-resistant and wear-resistant ceramic lining.

(II) background of the invention

The basic principle of the ceramic composite lining steel pipe is to use Al and Fe₂O₃(or Fe)₃O₄) The aluminothermic centrifugal reaction can self-maintain by means of heat release, and instantaneously melts reactant iron and alumina, under the action of centrifugal force, the alumina with light specific gravity is distributed on the inner wall of the steel pipe, and the iron with high density is distributed between the steel pipe and the alumina ceramic, and combines the steel pipe and the ceramic layer. Al and Fe₂O₃(or Fe)₃O₄) The reaction formula (c) is as follows:

chinese patent 90107244.3 discloses a technology for manufacturing corrosion-resistant and wear-resistant ceramic steel tube, in which Al + Fe₂O₃(or Fe)₃O₄) Simultaneously adding an additive SiO into the materials₂And one or two alkali metal oxides (in Na)₂O、K₂O、Li₂O) and one or two alkaline earth metal oxides RO (selected from MgO, CaO, BaO and ZnO), preheating the uniformly mixed materials or the steel tube strip materials to 100-300 ℃, igniting the materials, and performing reaction sintering under the action of centrifugal force to form a non-permeable compact ceramic coating with the thickness of about 2mm on the inner wall of the steel tube. SiO 2₂RO and R₂The raw material O is preferably feldspar, talc, wollastonite, and other mineral materials, and the total weight of the additives is 3-10% (by weight), wherein SiO₂1 to 6%, RO 1 to 5%, R₂O is 0 to 3%. The technology has the defects of preheating, complex process, high raw material cost and the like.

(III) the invention content:

the technical problems to be solved by the invention are as follows: reduce the cost of raw materials and Al₂O₃Melting point, improving its fluidity, thereby improving the surface quality of the ceramic layer. The technical scheme of the invention is as follows: a method for manufacturing a ceramic lining steel pipe comprises the following raw materials of Al and SiO₂The manufacturing method comprises bakingThe method comprises the steps of feeding, proportioning, mixing, charging and ignition sintering, and is characterized in that acid slag materials (generated by iron ore dressing) and Al and SiO are used₂Drying, mixing, igniting, reacting and sintering under the action of centrifugal force to form compact ceramic coating on the inner wall of the steel pipe. No heating is required before ignition. The specific manufacturing method comprises the following steps:

1. and (3) detecting the components of the acid slag: and (5) checking items and requirements: the Fe content is more than 60 percent, the S content is less than 0.7 percent, and the P content is less than 0.04 percent;

2. drying materials: mixing Al powder, acid slag and SiO₂And (4) respectively baking and dehumidifying at38-75 ℃, and detecting the moisture.

3. Selecting materials: and screening the raw materials by using a 150-200 mesh screen.

4. Preparing materials: calculating the total material amount according to the weight of the steel pipe, and mixing the materials according to the following proportion:

al and acid slag material is 1: 2.5-3.5,

SiO₂the addition amount is equal to the total weight of the raw materials multiplied by 4-5.5%.

5. Mixing materials: adding the three raw materials into a mixer and mixing uniformly.

6. Loading and pipe making: adding the mixed raw materials into a steel pipe, uniformly distributing the materials, starting the pipe making machine, igniting the steel pipe when the rotating speed of the pipe making machine reaches 85-90% of the specified rotating speed (900-1600 revolutions), and performing reaction sintering under the action of centrifugal force to form a ceramic coating with a smooth surface on the inner wall of the steel pipe.

The invention has the advantages that the cheap acid slag material (less than 100 yuan/ton) is used for replacing Fe₂O₃(or Fe)₃O₄) The powder material (3000 yuan/ton) greatly reduces the cost of raw materials, and the acid sludge material contains a certain amount of Ca, Mg, Si and other low-melting-point phase substances besides iron, so that Al is generated in the reaction₂O₃The melting point is greatly reduced, the fluidity is improved, and the surface quality of the ceramic layer is improved. Preheating is not needed, and the process is simplified; and a self-made electric ignition device is adopted, and two ends of the electric ignition device are ignited, so that the electric ignition device is safe and reliable.

(IV) specific embodiment:

example 1:

80 g of aluminum powder (150-200 meshes), 240 g of acid slag material (150-200 meshes) and 13 g of SiO₂Drying, mixing, placing into 20 steel tube with diameter of 108mm, thickness of 4mm and length of 150mm, fixing on tube making machine, starting ignition device when the rotation speed of centrifugal machine reaches 1170 rpm, and forming ceramic coating with thickness of 2mm on the inner wall of steel tube by reaction sintering. The surface of the ceramic layer is smooth and has no cracks, and the microhardness is more than or equal to 1200kg/mm²Density of 3.20g/cm³The crushing strength of the composite steel pipe is 300-330 Mpa, the shear strength is 20-25 Mpa, and the corrosion resistance (10% HCl, 20 ℃, one month) is less than 0.05g/m²H, thermal shock resistance 600 ℃/15 times, no crack and no drop.

Example 2:

100 g of aluminum powder (150-200 meshes), 320 g of acid slag material (150-200 meshes) and 21 g of SiO₂Drying, mixing, placing into 20 steel tube with diameter of 108mm, thickness of 4mm and length of 150mm, fixing on tube making machine, starting ignition device when the rotation speed of centrifugal machine reaches 1300 r/m, and forming ceramic coating with thickness of 2.2mm on the inner wall of steel tube through reaction sintering. The surface of the ceramic layer is smooth and has no cracks, and the microhardness is more than or equal to 1200kg/mm²Density of 3.19g/cm³The crushing strength of the composite steel pipe is 300-330 Mpa, the shear strength is 20-25 Mpa, and the corrosion resistance (10% HCl, 20 ℃, one month) is less than 0.05g/m²H, thermal shock resistance 600 ℃/15 times, no crack and no drop.

Claims

1. A method for manufacturing a ceramic lining steel pipe comprises the following raw materials of Al and SiO₂The manufacturing method comprises the steps of material drying, material proportioning, material mixing, material loading and ignition sintering, and is characterized in that: the raw materials also comprise acid slag materials generated by iron ore dressing, and the acid slag materials are mixed with Al and SiO₂Drying, mixing, igniting, reacting and sintering under the action of centrifugal force to form compact ceramic coating on the inner wall of the steel pipe.

2. The method for manufacturing a ceramic lined steel pipe as claimed in claim 1, wherein: the specific manufacturing method comprises the following steps:

(1) and (3) detecting the components of the acid slag: and (5) checking items and requirements: the Fe content is more than 60 percent, the S content is less than 0.7 percent, and the P content is less than 0.04 percent;

(2) drying materials: mixing Al powder, acid slag and SiO₂Respectively baking at 38-75 ℃ for moisture removal, and detecting the absence of moisture;

(3) selecting materials: screening the raw materials by using a 150-200 mesh screen;

(4) preparing materials: calculating the total material amount according to the weight of the steel pipe, and mixing the materials according to the following proportion:

al and acid slag material is 1: 2.5-3.5,

SiO₂the addition amount is equal to the total weight of the raw materials multiplied by 4-5.5%;

(5) mixing materials: adding the three raw materials into amixer and mixing uniformly;

(6) loading and pipe making: adding the mixed raw materials into a steel pipe, uniformly distributing the materials, starting the pipe making machine, igniting the steel pipe when the rotating speed of the pipe making machine reaches 85-90% of the specified rotating speed of 900-1600 rpm, and performing reaction sintering under the action of centrifugal force to form a ceramic coating with a smooth surface on the inner wall of the steel pipe.

3. A method of manufacturing a ceramic lined steel pipe as claimed in claim 1 or 2 wherein no heating is required prior to ignition.

4. The method for manufacturing a ceramic lined steel pipe as claimed in claim 1, wherein: the acid slag material contains a certain amount of Ca, Mg and Si low-melting-point phase substances besides iron.