The effect of roller adjustment on the quality of ERW has a process called roller adjustment when producing ERW pipes. During the production process, the roller is damaged or worn seriously. It is necessary to replace the unit on the part of the roller, or to produce a certain number of rollers continuously to meet the needs of the replacement of the whole roller. At this point, the roller should be adjusted to achieve excellent steel quality. If the roll adjustment is not good, it is easy to form the change of steel pipe seam, lap welding, edge wave, indentation or scratch on the surface of drum and pipe body, elliptical steel pipe and so on. Therefore, the roll adjustment prompt should be mastered when the roll is replaced.

1, choose the right process From the comparison of several large longitudinal welded pipe technology and the development analysis of large longitudinal welded pipe technology in the world, UOE is the main DSAW tube unit in the world to produce high strength pipeline steel pipe. Its production capacity is large and the quality of the product is good. The developed countries in the world have established such a unit. China is a big iron and steel country. It is also a country with a large number of oil and gas pipelines. It is very necessary to build 1 or 2 advanced UOE devices in the world to produce high quality steel pipes for oil and gas pipelines. In addition, 2 to 3 sets of other double tube units can be constructed, such as C pressure molding and continuous forming (CFE). Although the output of these welded pipe units is low, they have less investment, quick construction and good flexibility. Good quality and strong ability to adapt to the market. In order to adapt to the development of the pipeline industry in China, the pipeline will gradually be DSAW tube, and the spiral welded pipe market is gradually transformed into the straight welded pipe market. This indicates that the construction of large longitudinal welded pipe will have a good prospect.

he straightening method of DSAW pipe: One, the DSAW tube is bent in the same direction Reason: Welding normalization is insufficient, the pipe has thermal stress on the welding side, and bent in one direction after cooling. Solutions: 1, adjust the middle roller, properly increase the deflection curve; 2, two straightening; 3, the whole tempering pipe can not be straightened directly.

1, choose the right process From the comparison of several large longitudinal welded pipe technology and the development analysis of large longitudinal welded pipe technology in the world, UOE is the main DSAW tube unit in the world to produce high strength pipeline steel pipe. Its production capacity is large and the quality of the product is good. The developed countries in the world have established such a unit. China is a big iron and steel country. It is also a country with a large number of oil and gas pipelines. It is very necessary to build 1 or 2 advanced UOE devices in the world to produce high quality steel pipes for oil and gas pipelines. In addition, 2 to 3 sets of other double tube units can be constructed, such as C pressure molding and continuous forming (CFE). Although the output of these welded pipe units is low, they have less investment, quick construction and good flexibility. Good quality and strong ability to adapt to the market. In order to adapt to the development of the pipeline industry in China, the pipeline will gradually be DSAW tube, and the spiral welded pipe market is gradually transformed into the straight welded pipe market. This indicates that the construction of large longitudinal welded pipe will have a good prospect.

There are many ways to connect carbon steel seamless pipes. Now lists several common methods: A, compression type; B, real-time connection; C, compression; D, push; E, conical thread; F, socket welding; G, flanged connections; h, welding and welding with traditional derived series connections.

The European Commission announced on the 18th that it has informed the World Trade Organization of a list of products that may impose tariffs on the United States. If the United States imposes tariffs on steel and aluminum on the EU, the EU will take retaliatory measures. The EU stated that the retaliatory measure is intended to compensate the EU for the impact of the addition of steel and aluminum tariffs in the same way. Once the measures taken by the EU take effect, it will be an effective safeguard measure. Before the EU notified the WTO, it had published the list of retaliations in the “Official Gazette” of the EU, which may take effect on June 20.

For the United States to impose tariffs on imports of steel and aluminum products, the European Union, Japan and other regions and countries have recently brewing response measures, ready to fight back at the level of the World Trade Organization (WTO), and stressed that through strengthening regional cooperation to resist the threat of trade protection.

In the ultrasonic detection of DSAW tube, how to identify and determine echo is a key issue. By analyzing the actual ultrasonic detection characteristics of double sided submerged arc welded pipe, the influence of ultrasonic defect signal or non defect signal and the influence of the radius of curvature of steel tube on the defect position are analyzed, including isolation, inclusions of ultrasonic echo signal, crack and base metal stratification. In this paper, the causes and identification methods of four kinds of false defect waves are summarized, such as the reflection wave of the coupling mixture, the reflection wave on the weld surface, the reflection wave caused by the upper and lower dislocation on the weld, and the accuracy of the defective ripple recognition of the defect free wave formed by the weld height or the bottom cut. It provides a new idea and a new direction for the actual ultrasonic detection of the DSAW pipeline.

There are many ways to connect carbon seamless steel pipe, and now several commonly used methods are listed: a, compression type; b, live connection; c, compression; d, push; e, taper thread; f, socket welding; g, live flange connection; h, welding and welding and the traditional combination of the derivative Series of connections.

The straightening method of DSAW tube: One, the DSAW tube is bent in the same direction Reason: Welding normalization is insufficient, the pipe has thermal stress on the welding side, and bent in one direction after cooling. Solutions: 1, adjust the middle roller, properly increase the deflection curve; 2, two straightening; 3, the whole tempering pipe can not be straightened directly.

For the United States to impose tariffs on imports of steel and aluminum products, the European Union, Japan and other regions and countries have recently brewing response measures, ready to fight back at the level of the World Trade Organization (WTO), and stressed that through strengthening regional cooperation to resist the threat of trade protection.

After getting approval from the National Company Law Tribunal (NCLT) in India on Tuesday, the India Steel Corp (Tata Steel) will open a takeover process for the bankrupt Steel Corp (Bhushan Steel). The industry expects that the India flat material industry will be further integrated. In the iron and steel industry in India, 6 companies account for 85% of the flat material production capacity. They are Tata Steel, JSW Steel, Steel Authority of India, Pu Shao steel, Bhushan Power and Steel Corp (Essar Steel). The last three companies are going through bankruptcy proceedings according to the new bankruptcy law of India.

DSAW pipe is made of steel plate as raw material, and is often extruded by automatic double-wire double-sided submerged arc welding process. DSAW pipe is simple, high efficiency and low cost. In the steel pipe forming steel plate deformation evenly, the residual stress is small, does not appear to scratch the surface of the phenomenon. In the diameter and thickness of the steel pipe size specifications can be used flexibly in the production of large diameter thick seam steel pipe advantage is more obvious. In the production process can be pre-welded after welding inside and outside, to ensure that welding does not appear wrong side, welding bias and not penetration and other defects, the quality of welding control easier.

The main factors that affect the quality of seamless steel tube machining are machine tools, knives, fixtures, workpiece blanks, process methods and processing environment. To improve the quality of seamless steel tube cutting, we must take appropriate measures in these areas, such as reducing machine work error, the correct selection of cutting tools to improve the quality of blanks, reasonable arrangements for the process to improve environmental conditions.

DSAW pipes are used in the following cases: (1) for the pipeline peak adjustment, because the gas consumption of the users is very uneven, the pipe pressure fluctuates frequently, the steel pipe bears greater alternating stress, and the pipe defects are extended under the action of alternating stress. If the weld is used, the defect probability of the spiral welded pipe is high, and the safety operation of the pipe will not be guaranteed.

1. the quality inspection of the DSAW pipe should be carried out by the supplier's technical quality supervision. 2. the supplier must ensure that the delivered DSAW pipe meets the specifications of the corresponding product standard. The supplier has the right to check and verify the corresponding product standards. 3. the DSAW pipeline should be submitted for inspection in batches, and the batch rules should conform to the corresponding product standards.

First, the difference between the production process ERW carbon steel pipe is the hot rolled coil through the continuous roll forming, the use of high-frequency current skin effect and proximity effects, so that the edge of the coil heat fusion, pressure in the squeeze roller under pressure welding to achieve production. Therefore, erw carbon steel pipe residual stress is small, through the weld heat treatment, sizing, straightening, water pressure and other processes, the residual stress to further release and reduce. Practice has proved that erw carbon steel pipe in the storage and use of residual stress on the steel pipe does not affect. Without any welding wire, the weld in the physical properties and chemical composition with the plate exactly the same. The quality of the erw carbon steel pipe depends on the quality of the sheet.

ERW carbon steel pipe welding advantages: The resistance welding of ERW carbon steel pipe is a way of connecting the workpiece by welding between two electrodes, and applying the current, the application of the current through the thermal resistance produced by the surface of the workpiece and adjacent areas to heat it into the form of molten or plastic, so that the metal is connected.

1, Outside diameter tolerance Seamless pipe: the use of hot-forming process, the sizing is about 8000C to complete the steel pipe raw material composition, cooling conditions and roll cooling state of its outer diameter have a greater impact, so the outer diameter control is difficult to be accurate and the fluctuation range is larger. ERW pipe: the use of cold forming, through the 0.6% reduction of diameter to complete the sizing, the process temperature is basically constant at room temperature, so the outer diameter control is accurate, the fluctuation range is small, is conducive to eliminate black buckle; 2, Wall thickness tolerance Seamless pipe: wall thickness control accuracy limit is 0.9mm.

Notes of erw carbon steel pipe in winter:

In May 4, 2018, the South African International Trade Management Commission (ITAC) announced that in November 15, 2012, the southern African Customs Union (SACU) imposed anti-dumping duties on six corner screw products imported from China, which expired in November 15, 2017. Southern African Customs Union related industries did not apply for sunset review prior to the termination of the anti-dumping measures. Therefore, with the approval of the ITAC final and the approval of the Ministry of trade and industry of South China, the anti-dumping measures mentioned above have been terminated on schedule.