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.

The steel billet is the product obtained by casting the molten steel produced by the steelmaking furnace. Steel billets from the manufacturing process can be divided into two types: die casting and continuous casting billet, the current casting process has been basically eliminated. Continuous cast steel billet and rectangular billet mainly carbon steel, low carbon low silicon cold rolled material, high quality carbon structural steel, low alloy high strength steel, special steel as the representative.

Macroscopic analysis of cracking Casing pipe crack direction for the horizontal, crack propagation along the circumference, the circumference of about 460mm. The flow can flow from the outer wall of the casing along the middle of the crack into the <24415mm casing, indicating that part of the crack has penetrated the casing wall thickness.

ASTM A513 erw carbon steel pipe covers round, square, rectangular, and special shape tubing. Types of astm a513 erw carbon steel pipe

Seamless steel pipe is a kind of long steel with hollow section and no joints. Smls pipe is used for conveying fluid pipe, structure with seamless steel tubes, compared to the solid round steel, in the bending torsional strength phase at the same time, the weight is lighter, is a kind of economic cross section steel, widely used in the manufacturing of structural and mechanical parts, such as petroleum drill pipe, auto transmission shaft, bicycle frame and construction of steel scaffolding and so on. Smls pipe made of high quality carbon steel or alloy steel, hot-rolled, cold-rolled (pull) of the points.

Brazil's imports of long timber in April dropped by 7.03% compared to the same period last year, mainly because of the decrease in imports from Korea and Turkey. According to the data released by the Brazil Ministry of trade in May 4th, Brazil imported 14 thousand and 800 tons of non alloy long timber in April, down 1 thousand and 100 tons in last year's 15 thousand and 900 tons. In April, Brazil imported the largest amount of timber from Korea, reaching 4556 tons, although it dropped by 15.1% from 5367 tons last year. Last month, only 249 tons of imported materials were imported from Turkey, down 85.6% from 1727 tons last year. In the first four months, Brazil imported 85 thousand tons of long timber, up 50.2% from 57 thousand tons last year. Due to higher costs and the revival of the construction industry, the price of rebar in Brazil was relatively strong in May. The monthly reference price of Brazil rebar has risen from 2200-2400 reya / tonnes (US $623-680 / ton) last month to 2380-2580 reya / tonnes (US $674-731 / ton) this month.

On May 8, 2018 at 9:16 in the morning, by the China Metallurgical jiaonai design and construction of the China 22mcc Belt and Road Initiative "key project - Malaysia Kuantan Industrial Park, 3 million 500 thousand tons of Steel Project No. 2 coke oven put into production smoothly.