LSAW pipes

• The purpose of cold expansion for lsaw steel pipe
• LSAW Process Flow
• The developing trend of LSAW steel pipe
• LSAW Production Size Range
• Advantages of LSAW steel pipe
• Pipe info chat for LSAW steel pipe
• LSAW equipment
• SSAW VS. LSAW
• LSAW steel pipe industry usage

Q345B steel polishing method

Polishing means a processing method by the action of mechanical, chemical or electrochemical, lower the q345b steel pipe surface roughness, to obtain a bright and smooth surface, and surface modification process making use of a flexible polishing tools and polishing abrasive particles or other media on the workpiece.

Q345B steel polishing method often used Polishing means a processing method by the action of mechanical, chemical or electrochemical, lower the q345b steel pipe surface roughness, to obtain a bright and smooth surface, and surface modification process making use of a flexible polishing tools and polishing abrasive particles or other media on the workpiece.

Polishing can not improve the dimensional accuracy or geometrical shape accuracy of q345b steel pipe, but can obtain a smooth surface or specular gloss, sometimes to be used to eliminate gloss. Usually buff as a polishing tool. Buff is generally made with multilayer canvas, leather crafted stacked, on both sides clamped with a metal circular plate, its rim coated abrasive mixture of powder and oil and other uniform.

(1) Mechanical q345b steel polishing surface corrosion resistance. As we know, the mechanical polishing q345b steel corrosion resistance is significantly lower than the electrochemical polishing q345b steel pipe, mainly due to the cold mechanical q345b polishing surface hardened steel deformed layer high corrosion rate, coupled with in the mechanical polishing process, inevitably have abrasive particles embedded in the deformable layer, the corrosion rate of deformation layer increased greatly.

(2) electrochemical q345b steel polishing makes the metal surface hardening layer easy to be dissolved, and can lower the surface activity, what’s more, there is a continuous passivation film formed on the surface, significantly improved the corrosion resistance.

Mechanical Properties of Chinese low alloy steel: Q345B

Q345B steel is a Chinese standardized low alloy, medium tensile strength steel made with a hot-rolling process, and is used for a number of manufacturing purposes. It is a steel with less than 0.2 percent of its composition made up of carbon, less than 0.55 percent of its composition made of silicon and several impurities (mostly sulfur, chromium and nickel). This particular grade of steel is a 'general purpose' manufacturing steel in construction equipment field, such as Q345B is basic mateiral of making excavator bucket and long boom arms.

Mechnical property for Q345B low alloy structural steel:

1, Yield Strength

A yield strength or yield point is the material property defined as the stress at which a material begins to deform plastically. Prior to the yield point the material will deform elastically and will return to its original shape when the applied stress is removed, Yield strength of Q345B is 345 MegaPascals. Like most steels of its grade, it suffers elongation before it pulls apart, typically at 20-21 percent of its initial length.

2, Tensile strength

The tensile strength of a material is the maximum amount of tensile stress that it can take before failure, for example breaking. Steel tensile strength is expressed in units of force divided by cross sectional area; in the Metric system, this unit is known as the Pascal. One Pascal is a Newton (the force needed to accelerate a one kilogram object to a velocity of one meter per second) per square meter. The tensile strength of Q345B steel is rated at 470 to 660 MegaPascals (where mega is million).

Thickness (mm)
Q345B	≤ 16	> 16 ≤ 35	> 35 ≤ 50	>50
Yield strength (≥Mpa)	345	325	295	275
Tensile strength (Mpa)	470-630

Steel tensile strength is expressed in units of force divided by cross sectional area; in the Metric system, this unit is known as the Pascal. One Pascal is a Newton (the force needed to accelerate a one kilogram object to a velocity of one meter per second) per square meter. The tensile strength of Q345B steel is rated at 470 to 630 MegaPascals (where mega is million) and a yield strength (where the material starts to thin and pull like taffy) at 345 MegaPascals. Like most steels of its grade, it suffers elongation before it pulls apart, typically at 20-21 percent of its initial length.

Chemical composition for Q345B low alloy structural steel (Heat Analysis Max%)

Main chemical elements composition of Q345B
C	Si	Mn	P	S	V	Nb	Ti
0.20	0.55	1.00-1.60	0.040	0.040	0.02-0.15	0.015-0.060	0.02-0.20

The equivalent steel grade with Q345B are EN 10025-2 S355JR,ASTM A572/A572 A572 Grade 50 and DIN 17100 St52-3.

Worldwide equivalents of grade Q345B:The density of Q345B steel is approximately 7.8 (where water is 1.0), and it is commonly available in thicknesses ranging from 2 mm to 12.7 mm (12.7 mm is approximately half-inch thick plates), with sheets typically sold in 1 to 1.35 meter wide splits.

EU EN

USA -

Germany DIN,WNr

Japan JIS

France AFNOR

England BS

Canada HG

European old EN

Italy UNI

Belgium NBN

Spain UNE

China GB

Sweden SS

Inter ISO

Portugal NP

India IS

S355JR (1.0045)

A572 A678Gr.A SSGrade50

St52-3

SM490A SS490

E36-2

50B

350W 350WT

Fe510B

Fe510B

AE355B

AE355B

Q345B Q345C

2132-01

E355C Fe510B

FE510-B

IS961

The major benefit of this grade of steel is its mild temper. It's easy to form and easy to weld.

LSAW pipes are mainly used as long distance transportation pipeline for oil, gas, liquid coal etc. on land and offshore.
And also can be applied as construction pipes on offshore platform, power station, petrochemistry and city construction etc.

LSAW pipes Production Range

LSAW (Longitudinally Submerged Arc Welded Steel pipes) in leaflets plate as raw material, the steel plate in the mold or molding machine pressure (volume) into using double-sided submerged arc welding and flaring from production.

Range of LSAW pipes for oil and gas pipeline

• Legnth:8-12.15m
• Material: API 5L Gr.B-X80
• Standard: API spec. 5L; GB9711.1-97

Range of LSAW pipes applied in construction

Range of roller pipes:

• Outer diameter: Ф1200-3800mm
• Wall thickness: 12-120mm
• Unit length (max) 3.2m.

Note: The specification in the table is available to Q345.

Remarks:non-standard dimensions pipes can be produced to customer specifications.

Range of Roller Pipes

Number	Technical parameter	Unit	HQW11s-120X3200
1	Material yield limited	Mpa	245	345	345
2	Wall thickness	mm	120	100	110
3	Maximum pre-bending thickness	mm	110	90	100
4	Maximum width of steel plate	mm	3200	3200	3200
5	Minimum diameter of fully loaded rolling steel plate	mm	2500	1600	1600

Range of roller pipes:

• Outer diameter: Ф1200-3800mm
• Wall thickness: 12-120mm
• Unit length (max) 3.2m.

The developing trend of LSAW steel pipe

The developing trend of LSAW steel pipe in the future:

• in terms of the onshore gas,with the large diameter LSAW steel pipe, its single-tube gas transmission capacity could reach the level of 50 billion cubic meters / year, pipe diameter can reach ф1422mm, steel grade achieve X80, and gas transmission pressure can reach 12MPa;
• in terms of the ocean steel pipe, the gas pipeline develops towards the direction of deep-sea pipeline (> 1500 meters), marine structural tube towards the direction of high-intensity, large wall thickness, for example ф610mm×31.8mm, X65 grade;
• in terms of business management, plate and pipe integration (steelmaking - Continuous Casting - rolled plate - pipe manufacturing) is the future development trend, for example in Japan and India plate and strip production line is always equipped with a welded steel pipe unit;
• entering the market of high-grade structural tubes, this is an important question to be considered by the LSAW steel pipe production line manufacturer when deploying the device, so it is necessary to set the preheating device before pre-welding, or set the heat treatment process and so on;
• in marketing, in addition to oil and gas pipelines, there is slurry pipelines;
• anti HIC tube and anti deformed tube are with a considerable market prospect, can be used to transport acid gases and improve the ability against external environmental damage in harsh geological conditions (landslides, mudslides, earthquakes).

Technical support for LSAW pipes

Longitudinally Submerged Arc Welded Process Flow
(LSAW Pipes)with JCOE forming mode

Our technical support for ERW , SSAW & LSAW stel pipe

Mainly as a field gathering pipe and internal high-pressure natural gas pipeline of small-caliber, long-distance pipelines for oil and gas a small number, the vast majority of long-distance pipeline is the use of high-frequency straight seam welded pipe (ERW), spiral submerged arc welded pipe (SSAW), LSAW steel pipe (LSAW) three.

Inspection & Test Plan for LSAW

LSAW (Inspection & Test Plan for LSAW) in leaflets plate as raw material, the steel plate in the mold or molding machine pressure (volume) into using double-sided submerged arc welding and flaring from production.

The purpose of cold expansion for lsaw steel pipe

After cold expansion for lsaw steel pipe, steel tube and pipe end diameter will increase by about one percent difference in diameter of the diameter, roundness, and the pipe ends are greatly improved, also have greatly improved the straightness of the steel pipe, steel pipea length of about 0.5% reduction in wall thickness decreases by about 0.8%.

Q345B steel polishing method

Polishing means a processing method by the action of mechanical, chemical or electrochemical, lower the q345b steel pipe surface roughness, to obtain a bright and smooth surface, and surface modification process making use of a flexible polishing tools and polishing abrasive particles or other media on the workpiece .

The LSAW steel pipe producing equipments

The major equipment such as Plate Edge Milling Machine, Plate Edge Crimping Machine, Pipe Forming Press, Tack Welding Machine and Pipe Expander all adopt the technology and equipment of SMS MEER. The SMS MEER is the most famous special manufacturer to design and manufacture the whole production line equipment for LSAW pipe in the world . They have supplied all kinds of steel pipe manufacturing equipment for plenty of LSAW pipe manufacturers in the world and have got a very good reputation in this field.

LSAW produce Technology Center

As a superior technology center has been establish ed including the domestic first-class chenical laboratory,mechanics laboratory, the metallography test laboratory and welding laboratory with advanced equipments for inspection and test Accordingly,it can provide a comprehensive inspection for the raw material and the finished products so that it guaran test the high quality of products.

Weled steel pipe specification, Standard and identification