Black carbon steel pipe can be welded.
Black carbon steel pipes are made by perforating steel ingots or solid round steel into capillary pipes, and then hot rolling, cold rolling or cold drawing.
Black carbon steel pipes are divided into two different types based on the manufacturing method
1. Seamless pipe
Seamless pipe is a long strip of steel with a hollow section and no seams around it. According to the production method, seamless pipes can be divided into hot-rolled seamless pipes and cold-rolled seamless pipes. Cold rolling is rolling at room temperature, while hot rolling is rolling above the recrystallization temperature.
2. Welded pipe
Welded pipe is a steel pipe made of steel plates or strips that are welded after being curled and formed. The length is generally 6 meters. The production process of welded steel pipes is simple, the production efficiency is high, there are many varieties and specifications, and the equipment investment is low, but the general strength is lower than that of seamless steel pipes.
Types of welded pipes
(1) Classification by use
It is further divided into general welded pipes, galvanized welded pipes, oxygen blown welded pipes, wire casings, metric welded pipes, roller pipes, deep well pump pipes, automotive pipes, transformer pipes, welded thin-walled pipes, welded special-shaped pipes, scaffolding pipes and spiral welded pipes .
General welded pipe: General welded pipe is used to transport low-pressure fluid. It can also be made of other mild steels that are easily weldable. Steel pipes are subject to hydraulic pressure, bending, flattening and other experiments, and have certain requirements for surface quality. The delivery length is usually 4-10m, and delivery of fixed length (or multiple lengths) is often required. The specifications of welded pipes are expressed in nominal diameter (millimeters or inches). The nominal diameter is different from the actual. According to the specified wall thickness, there are two kinds of welded pipes: ordinary steel pipes and thickened steel pipes.
Galvanized steel pipe: In order to improve the corrosion resistance of steel pipes, general steel pipes (black pipes) are galvanized.
Oxygen blowing welded pipe: used as oxygen blowing pipe for steelmaking. Generally, small diameter welded steel pipe is used, with eight specifications ranging from 3/8 inch to 2 inch. Made of 08, 10, 15, 20 or Q195-Q235 steel strip. In order to prevent corrosion, some are aluminized.
Wire casing: It is an ordinary carbon steel electric welded steel pipe. It is used in concrete and various structural power distribution projects. The commonly used nominal diameter is from 13-76mm. The wire sleeve has a thin wall and is mostly used after being coated or galvanized, requiring a cold bending test.
Metric welded pipe: specifications are used in the form of seamless pipes, welded steel pipes expressed in outer diameter * wall thickness mm, with tropical or cold zone welding of ordinary carbon steel, high-quality carbon steel or general low alloy steel, or with tropical welding Then it is made by cold drawing method. Metric welded pipes are divided into general-purpose and thin-walled pipes. They are generally used as structural parts, such as transmission shafts, or to transport fluids. Thin-walled pipes are used to produce furniture, lamps, etc. The strength and bending test of the steel pipe must be ensured.
Roller tube: used for belt conveyor roller electric welded steel pipe, generally made of Q215, Q235A, B steel and 20 steel, with a diameter of 63.5-219.0mm. There are certain requirements for the curvature of the pipe, the end face to be perpendicular to the center line, and the ovality. Generally, water pressure and flattening tests are performed.
Transformer tube: used to manufacture transformer radiator tubes and other heat exchangers. It is made of ordinary carbon steel and requires flattening, flaring, bending and hydraulic testing. Steel pipes are delivered in fixed lengths or multiple lengths, and there are certain requirements for the bending of the steel pipes.
Special-shaped pipes: square pipes, rectangular pipes, hat-shaped pipes, hollow rubber steel pipes for doors and windows welded from ordinary carbon structural steel and 16Mn and other steel strips. They are mainly used as agricultural machinery components, steel windows and doors, etc.
Electrically welded thin-walled tubes: mainly used to make furniture, toys, lamps, etc. In recent years, thin-walled tubes made of stainless steel strips have been widely used in high-end furniture, decorations, fences, etc.
Spiral welded pipe: It is made by rolling low-carbon carbon structural steel or low-alloy structural steel strips into pipe blanks at a certain spiral angle (called forming angle), and then welding the pipe seams. It can be made of narrower pipes. Strip steel produces large diameter steel pipes. Spiral welded pipes are mainly used for oil and natural gas transmission pipelines, and their specifications are expressed by outer diameter * wall thickness. Spiral welded pipes are either single-sided or double-sided. Welded pipes should ensure that the hydraulic pressure test, tensile strength and cold bending performance of the weld meet the regulations.
(2) Classification by production method
a. According to the process - arc welded pipe, resistance welded pipe (high frequency like ERW steel pipe, low frequency), gas welded pipe, furnace welded pipe.
b. According to the welding seam - straight seam welded pipe, spiral welded pipe.
(3) Classification according to cross-sectional shape
a. Simple cross-section steel pipes - round steel pipes, square steel pipes, oval steel pipes, triangular steel pipes, hexagonal steel pipes, rhombus steel pipes, octagonal steel pipes, semi-circular steel pipes, and others.
b. Complex cross-section steel pipes - unequal hexagonal steel pipes, five-petal plum blossom-shaped steel pipes, double-convex steel pipes, double-concave steel pipes, melon-shaped steel pipes, conical steel pipes, corrugated steel pipes, watch case steel pipes, and others.
(4) Classified by wall thickness
Thin-walled steel pipes, thick-walled steel pipes.
(5) Classification by end shape
Divided into round welded pipes and special-shaped (square, flat, etc.) welded pipes.
Black carbon steel pipes are made by perforating steel ingots or solid round steel into capillary pipes, and then hot rolling, cold rolling or cold drawing.
Black carbon steel pipes are divided into two different types based on the manufacturing method
1. Seamless pipe
Seamless pipe is a long strip of steel with a hollow section and no seams around it. According to the production method, seamless pipes can be divided into hot-rolled seamless pipes and cold-rolled seamless pipes. Cold rolling is rolling at room temperature, while hot rolling is rolling above the recrystallization temperature.
2. Welded pipe
Welded pipe is a steel pipe made of steel plates or strips that are welded after being curled and formed. The length is generally 6 meters. The production process of welded steel pipes is simple, the production efficiency is high, there are many varieties and specifications, and the equipment investment is low, but the general strength is lower than that of seamless steel pipes.
Types of welded pipes
(1) Classification by use
It is further divided into general welded pipes, galvanized welded pipes, oxygen blown welded pipes, wire casings, metric welded pipes, roller pipes, deep well pump pipes, automotive pipes, transformer pipes, welded thin-walled pipes, welded special-shaped pipes, scaffolding pipes and spiral welded pipes .
General welded pipe: General welded pipe is used to transport low-pressure fluid. It can also be made of other mild steels that are easily weldable. Steel pipes are subject to hydraulic pressure, bending, flattening and other experiments, and have certain requirements for surface quality. The delivery length is usually 4-10m, and delivery of fixed length (or multiple lengths) is often required. The specifications of welded pipes are expressed in nominal diameter (millimeters or inches). The nominal diameter is different from the actual. According to the specified wall thickness, there are two kinds of welded pipes: ordinary steel pipes and thickened steel pipes.
Galvanized steel pipe: In order to improve the corrosion resistance of steel pipes, general steel pipes (black pipes) are galvanized.
Oxygen blowing welded pipe: used as oxygen blowing pipe for steelmaking. Generally, small diameter welded steel pipe is used, with eight specifications ranging from 3/8 inch to 2 inch. Made of 08, 10, 15, 20 or Q195-Q235 steel strip. In order to prevent corrosion, some are aluminized.
Wire casing: It is an ordinary carbon steel electric welded steel pipe. It is used in concrete and various structural power distribution projects. The commonly used nominal diameter is from 13-76mm. The wire sleeve has a thin wall and is mostly used after being coated or galvanized, requiring a cold bending test.
Metric welded pipe: specifications are used in the form of seamless pipes, welded steel pipes expressed in outer diameter * wall thickness mm, with tropical or cold zone welding of ordinary carbon steel, high-quality carbon steel or general low alloy steel, or with tropical welding Then it is made by cold drawing method. Metric welded pipes are divided into general-purpose and thin-walled pipes. They are generally used as structural parts, such as transmission shafts, or to transport fluids. Thin-walled pipes are used to produce furniture, lamps, etc. The strength and bending test of the steel pipe must be ensured.
Roller tube: used for belt conveyor roller electric welded steel pipe, generally made of Q215, Q235A, B steel and 20 steel, with a diameter of 63.5-219.0mm. There are certain requirements for the curvature of the pipe, the end face to be perpendicular to the center line, and the ovality. Generally, water pressure and flattening tests are performed.
Transformer tube: used to manufacture transformer radiator tubes and other heat exchangers. It is made of ordinary carbon steel and requires flattening, flaring, bending and hydraulic testing. Steel pipes are delivered in fixed lengths or multiple lengths, and there are certain requirements for the bending of the steel pipes.
Special-shaped pipes: square pipes, rectangular pipes, hat-shaped pipes, hollow rubber steel pipes for doors and windows welded from ordinary carbon structural steel and 16Mn and other steel strips. They are mainly used as agricultural machinery components, steel windows and doors, etc.
Electrically welded thin-walled tubes: mainly used to make furniture, toys, lamps, etc. In recent years, thin-walled tubes made of stainless steel strips have been widely used in high-end furniture, decorations, fences, etc.
Spiral welded pipe: It is made by rolling low-carbon carbon structural steel or low-alloy structural steel strips into pipe blanks at a certain spiral angle (called forming angle), and then welding the pipe seams. It can be made of narrower pipes. Strip steel produces large diameter steel pipes. Spiral welded pipes are mainly used for oil and natural gas transmission pipelines, and their specifications are expressed by outer diameter * wall thickness. Spiral welded pipes are either single-sided or double-sided. Welded pipes should ensure that the hydraulic pressure test, tensile strength and cold bending performance of the weld meet the regulations.
(2) Classification by production method
a. According to the process - arc welded pipe, resistance welded pipe (high frequency like ERW steel pipe, low frequency), gas welded pipe, furnace welded pipe.
b. According to the welding seam - straight seam welded pipe, spiral welded pipe.
(3) Classification according to cross-sectional shape
a. Simple cross-section steel pipes - round steel pipes, square steel pipes, oval steel pipes, triangular steel pipes, hexagonal steel pipes, rhombus steel pipes, octagonal steel pipes, semi-circular steel pipes, and others.
b. Complex cross-section steel pipes - unequal hexagonal steel pipes, five-petal plum blossom-shaped steel pipes, double-convex steel pipes, double-concave steel pipes, melon-shaped steel pipes, conical steel pipes, corrugated steel pipes, watch case steel pipes, and others.
(4) Classified by wall thickness
Thin-walled steel pipes, thick-walled steel pipes.
(5) Classification by end shape
Divided into round welded pipes and special-shaped (square, flat, etc.) welded pipes.
