Because SSAW pipe can be continuously formed by the coil width of the welding production, easy to automate the use of double-sided submerged arc welding, there are a variety of test methods to check the quality inspection of the weld. Therefore, the laying of pipelines, spiral welded pipe has been widely used. However, during the forming process, various pipe defects are generated due to process errors or due to other reasons that cause the operation to mature.

Cold drawing seamless pipe for precision mechanical structure, hydraulic equipment and good surface finish cold drawn or cold-rolled precision seamless steel tubes. High-precision drawing that diameter size accuracy (tolerance) strict, the outer surface finish, roundness, straightness, thickness uniformity is good.

Carbon Steel Weldability

UOE Pipe and JCOE Pipe

Standard and grade: ASTM a179 / ASME sa179 Delivery conditions: Annealing, normalizing, normalizing and tempering. The main tests are according to ASTM a213-09 and ASTM 1016 1. High pressure water pressure test: at least 10 maps. 2. Eddy current test, ultrasonic test Three. Mechanical test 4. OD and weight tolerance test.

Spiral submerged arc welded pipe manufacturing process: (1) strip, wire, flux of raw materials. Before entering the physical and chemical must undergo rigorous testing.

Boiler tube hardness is one of the important factors that determine the quality of high pressure boiler tubes.

Welding materials under specified conditions, the construction of components required by the design of welding methods, and to meet the intended use requirements. Through the welding material, welding, component type and the requirements of the four factors.

Cold drawing seamless pipe for precision mechanical structure, hydraulic equipment and good surface finish cold drawn or cold-rolled precision seamless steel tubes. High-precision drawing that diameter size accuracy (tolerance) strict, the outer surface finish, roundness, straightness, thickness uniformity is good.

ASTM a179 seamless steel pipe manufacturing process should be cold and stretch. Product analysis and thermal engineering are performed on steel materials that should meet the chemical composition of the two required carbon, manganese, phosphorus and sulfur. "Steel materials should also undergo flattening hardness test, flaring test, flange test and static test.

Precision seamless pipe is used for hydraulic cylinders, automobiles and other mechanical devices. Features: High-precision, high brightness, the inner and outer surface of the tube with high clean and no oxidation, and finally good mechanical properties of pipe, no leakage of high pressure, cold bending no crack flares flat deformation, to ensure that all services Efficient operation.

(1) strip, wire, flux of raw materials. Before entering the physical and chemical must undergo rigorous testing. (2) the use of submerged arc welding, the use of single or double wire in the strip submerged arc welding with steel head and tail docking. (3) Prior to forming, the strip is flattened, cut, edged, shaved, surface cleaned, and trimmed after shipping. (4) Use electric contacts on both sides of the conveyor to control the cylinder pressure to ensure the smooth delivery of the strip.

Ceramic tube and ordinary steel, wear-resistant alloy steel pipe, artificial stone and plastic pipe, steel pipe and other essential differences between rubber. Ceramic tube is steel, corundum. Corundum layer hardness 1100-1500 (90-98 Rockwell hardness), equivalent to tungsten cobalt hard gold. Abrasion resistance than carbon steel pipe 20 times higher than the performance of corundum wheel is much better. There are still a variety of corundum grinding wheel cutting hardened steel main wheels. Corundum corundum ceramic tube abrasive layer can be retracted. Wear-resistant ceramic tube corundum layer can be formed mainly by a few millimeters thick, Mohs hardness of 9, second only to diamond and silicon carbide, all the oxides, which is the highest hardness. Only about 20% of the tubes and components are alumina, most of which have a Mohs hardness of 7. Rare high-chromium wear-resistant alloy tube or Vickers hardness of about 400 (Rockwell hardness of about 50); Corundum less than the third. Therefore, wear-resistant alloy steel pipe, pipe wear and tear both the composition and organization, but also the wear resistance of ceramic pipe, in contrast, there has been a qualitative leap.

Seamless welding can use different gas types, the specific circumstances of gas welding, the use of shielding gas carbon dioxide, argon, helium, hydrogen and gas mixture. Advantage of melting gas welding is: linear arc is good, simple and easy to achieve all-position welding and automatic welding; arc heat concentration, small bath, welding speed, heat-affected zone is small, welding deformation, cracking ability and good welding quality. The disadvantage is not in the wind welding site, arc radiation strong.

Seamless Steel Pipe Manufacturing Process

Carbon steel hardness commonly used Brinell hardness, Rockwell hardness, Vickers hardness of three indicators to measure.

The reason of the cold crack is the process of the hardenability of the welding material which is easy to be cooled by the people when being welded. The cooling speed of the welding is too late for the residual hydrogen in the weld to escape. The molecular hydrogen of a hydrogen atom Of the metal pores cause a lot of pressure, so that the pressure of local metal cold bending cracks; focus on hydrogen embrittlement and hardening of the welding stress and tensile stress analysis at the same time prone to the formation of cold cracks.

Seamless steel pipe perforated hole production of steel. Welded steel pipe into a barrel and then welded. According to its production of seamless steel pipe and welded pipe method is divided into two. Seamless steel pipe using high-quality carbon steel or alloy steel, hot-rolled, cold-rolled (pull) points. Welded steel rolled into the tube plate, weld or spiral seam welding, in the manufacturing method, is divided into low pressure fluid welded steel pipe, spiral welded steel pipe, straight seam welded pipe, welded pipe. Seamless steel pipe can be used for a variety of liquids, gas pipelines. Welded pipe can be used for water pipes, gas pipes, heating pipes. Seamless steel pipe for important applications, such as pipes, barrels and other uniform, high pressure. General use of high-quality steel, alloy steel or even. The general purpose of the general use of steel compression steel, such as water pipes, gas pipes and so on

To achieve steel pipe manufacturing machine: Combined with specially designed equipment 1600mt bending machine, multi-roll plate bending machine, welding equipment, internal and external girth welding, size setting machine, solution annealing furnace and a series of other related machinery, is used to manufacture key applications Such as oil refining, fertilizer, LNG terminal pipelines, transnational pipelines.

Preheating is a process, or in the overall welding before the weldment weld area is hot. Particularly good welding high strength materials, work hardening tend to steel, thermal conductivity, thicker weldments, when the ambient temperature is too low, the weld zone often requires preheating before butt welding. The purpose of preheating is to reduce the cooling rate of the welded joint and the preheating temperature. As can be seen from the table, preheating can reduce the cooling rate, but does not affect the time to stay at high temperatures, which is very desirable. Therefore, when the weld steel has a tendency to quench, the main process of reducing the cooling rate and reducing the tendency of quenching is to heat rather than increase the input of energy.

Low-carbon steel refers to steel containing less than 0.25% carbon, low strength, low hardness and softness. It includes most of ordinary carbon steel and high-quality carbon structural steel, most of which are not used for heat treatment in engineering structures, but also for some mechanical parts required for carburizing heat treatment and other wear. Low carbon steel annealed ferrite and pearlite strength and hardness, ductility and toughness are low. Therefore, cold forming performance is good, and cold forming methods such as crimping, bending and punching can be performed. This mild steel pipe weldability. Mild carbon steels with carbon contents ranging from 0.10 to 0.30% are easy to accept for a variety of processes such as forging, welding and cutting, commonly used in the manufacture of chains, rivets, bolts, shafts and more.