1. ASTM A53 thick-walled seamless steel pipe hot rolling position were from the steel head 38,118m, mainly in the middle of the strip. 2. It is speculated that the gap starts at the middle of the width of the strip, because the rolling force and shear force in the rolling process cause the gap to be stretched to form a macroscopic macropore. 3. Seamless steel pipe in the cold rolling production process interrupted with the fracture surface smooth, no obvious before and after fracture surface defects. The microstructure of the fracture was observed, and the typical ductile ductile fracture morphology was observed. At the same time, the fracture was layered, the central dimple was larger, the dimple was narrowed near the surface, and the crack appeared the center fracture And the depth of fracture at the center is deep, and it is presumed that the stratified topography is closely related to the central segregation.

How to prevent the J55 ERW casing from clasping and attaching, the hollow section of the API ERW sleeve, a large number of pipes used for conveying fluid, such as oil, natural gas, gas, water transportation, etc. The use of steel pipe manufacturing ring can improve the utilization of materials, simplify the manufacturing process, save material and processing time, such as rolling bearing rings, Jack suites, and so on, has been widely used in the manufacture of steel.

Speaking of steel pipe materials, the professional manufacturers of steel pipe manufacturers are constantly improving their product quality requirements, but some necessary wear and tear is indispensable. Oxidation corrosion is sometimes present. What is the reason?

The three processes of electrochemical corrosion of ASTM A179 cold drawn seamless pipe are as follows: First of all, for urban gas system, because of the dense underground pipe network, the external power supply cathodic protection will interfere with other cold drawn steel tubes, which will cause their own interests and affect their family status. However, the use of the sacrificial anode protection method for the use of the cold drawn steel pipe than the negative metal and the cold drawn steel pipe does not appear. Therefore, the urban gas pipeline should adopt the antirust coating and the sacrificial anode combination.

1. ASTM A53 thick wall seamless steel tube hot rolling position away from the steel head 38118m, mainly located in the middle of the steel strip. 2. it is speculated that the gap formed by the rolling force and shear force during the rolling process is macroscopically large, so the gap begins in the middle of the strip width. 3. seamless steel pipe is smooth in the cold rolling process, and there is no obvious defect on the surface before and after fracture. The microstructure of fracture surface was observed and typical ductile ductile fracture morphology was observed. At the same time, the faults are distributed in layers, the central pits are larger, the pits are narrowed near the surface, the cracks appear in the center and the depth of the central fracture is deep, and the stratified topography is closely related to the central isolation.

There are more standards for steel products in the United States, mainly in the following categories: ANSI - the national standard of the United States AISI - American Steel Standards Association

Other countries and ISO stainless steel standards are provided to hot rolled (forged) steel, in addition to heating pressure processing steel, general heat treatment delivery (heat treatment requirements need to be stipulated in the contract). After heat treatment, surface treatment or surface treatment such as pickling, shot peening or turning and peeling is required. For cold or cold drawn or cold drawn steel or cold working conditions, or after heat treatment of pickling or shot peening or cold processing after heat treatment, after forming, grinding, polishing or further to varying degrees of hardening treatment and other state delivery.

The ASTM material standard is formulated by the American Institute of materials and testing. ASTM material standards can include chemical, mechanical, physical and electrical properties of materials. These standards include the description of test methods for building materials, and the size and shape of these materials. Local laws require that concrete and other building materials meet the ASTM standard before construction. It is widely used in ASTM A53 and ASTM A106.

The German n-TV news website reported that Eurofer severely criticized the United States for imposing punitive tariff measures, claiming that Trump’s move was “harmful” and could result in the loss of tens of thousands of jobs in Europe. A Eurofer spokesman said that European steelmakers will suffer heavy losses in their most important export markets and demand that the EU immediately issue protection measures for the steel industry. The U.S. tariff policy will result in a significant shift of the other involved steel companies to the European market. If the import of steel is significantly increased and the development of European companies is jeopardized, the introduction of protective measures is in principle in conformity with the WTO rules. Eurofer officials said that the European Commission has announced that it will take immediate action. This is a good thing. When the United States damages the international trading system, the EU cannot stand idly by.

On the 12th, local time, the US Department of Commerce decided in the final judgment of the annual anti-dumping tariffs for oil-specific pipes to impose a 75.81% anti-dumping tariff on South Korean steel company Nexteel and 6.75% anti-dumping tariffs on companies such as Worldsteel.

Spiral steel pipe should be tested before the factory mechanical properties and flattening test and flaring test, and meet the requirements of the standard requirements.

1. repair the mouth In order to ensure the welding quality, the welding is carried out before the complete inspection and correction, so that the pipe end, the oblique angle, the blunt edge and the roundness are in accordance with the interface size. When the individual steel pipe needs to be processed in the field, the gas welding is used and the slag is removed and the grinding wheel is reused with the grinding wheel. The operation procedure of the counter is to check the size of the interface connector, to clean the cavity, to determine and adjust the longitudinal joint of the staggered position of the steel tube, to the first pipe straight, to adjust the size of the gap between the counterpart, to the leveling mouth, to straight to straight, to the light point welding.

Why does oil drilling choose thick-walled seamless steel tubes?

Process equipment distinction: cold drawn seamless steel pipe is usually 0.5 ~ 100T single-chain or double-chain cold drawn machine. Finished seamless steel tubes are usually carried out on a two-roll mill where the steel pipe is rolled in a ring-shaped bore formed by a variable cross-section round hole and a stationary tapered head.

For the ASTM standard, the mechanical properties, chemical composition and metallurgical properties of different steels are different. There is a list of ASTM standards for different steel grades.

The non standard steel pipe is a kind of steel pipe which is compared with the national standard for the seamless steel pipe except the state standard. In the production of seamless steel pipe, the thickness of the wall thickness is classified according to the national conventional requirements and the thickness of the wall is classified, and it is allowed to have certain errors, which belongs to the national standard. In practical use, the national standard often has some limitations, which corresponds to the appearance of non-standard seamless steel tubes. The specifications of non-standard steel pipes complement the standard standard seamless steel pipe production, not that the quality of seamless steel pipe is compared to the national standard.

Black erw steel pipe is hot-rolled coil through the molding machine, the use of high-frequency current skin effect and proximity effects, so that the edge of the tube heating and melting, in the role of squeeze roller pressure welding to achieve production.

Introduction of welded pipe welding of submerged arc welding: 1, bubbles occur in the middle of the weld, the main reason is that hydrogen is still hidden in the weld metal in the form of bubbles, so eliminating the defects is the first step to remove the wire and weld corrosion, oil, moisture and humidity, followed by the need to dry the flux to remove water. In addition, increasing the current, reducing the welding speed and slowing down the melting speed of molten metal are also very effective.

The preweld quality of straight steel pipe includes weld quality and weld quality. (1) when the joint (i.e. the forming joint) has no wrong side or the wrong side is less than the specified value, the general error is less than or equal to 8%, and the maximum is not more than 1.5mm. (2) in order to ensure the suitable penetration depth and welding amount of the weld, it is necessary to ensure no cracking after welding, no burning phenomenon, and the height of the weld. There is no effect on the weld seam height. (3) continuous weld and good shape to ensure the final external welding quality. (4) there are no defects such as welding deviation, blowhole, crack, slag, welding and backing welding. The weld center deviation is less than 1mm. (5) no electric arc burns, little splash, no influence on pipe end groove and surface quality. (6) the weld metal is matched with the base metal, and the physical and chemical properties of the weld metal conform to the quality requirements.

Straight seam steel pipe fracture, hydraulic (pneumatic) parts in the design of the use of mechanical properties, brittle fracture is also related to the use of components temperature.

(1) the forming process of high frequency longitudinal welded pipe has little springback and little residual stress.