Factors affecting the welding quality of ERW welded pipe

 With the development of ERW welded pipe technology, its application fields continue to expand. ERW welded pipe uses the skin effect and proximity effect of the current to heat the edge of the tube blank to the welding temperature for extrusion and welding. Compared with seamless pipe, it is obvious that ERW pipe has a weld seam, and its performance depends largely on the quality of the weld seam.

The factors affecting the quality of welds are more complicated, including the chemical composition of raw materials, inclusions, banded structures, sickle bends, and edge burrs, which will all affect the quality of welds.

a. Inclusions and banded structures have a great influence on the impact toughness and flattening performance of welds. Excessive inclusions are easy to accumulate in the heat-affected zone of welds and easily form crack sources to cause cracking.

b. When the sickle bend and the edge burr are serious, it will cause misalignment, arc strike, weld deviation, inclusions are difficult to discharge, etc., which will reduce the quality of the weld.

Factors of high-frequency welding process level. The temperature, speed, extrusion amount and opening angle during welding will all affect the quality of the weld.

If the temperature is too high, the burr does not have a raised shape, the weld seam is flat, and the temperature is too low, the top of the outer burr is not smooth, and there is no intermittent raised shape on the burr line; the faster welding speed, it is easier to ensure the quality of the weld seam; in general, The amount of extrusion should refer to the wall thickness, and it is better to control it at about 5.0mm. For thick-walled pipes such as 10mm or more, the extrusion amount can be increased by 0.5-1mm; as the diameter and thickness of the pipe change, the opening angle should also be adjusted appropriately.

The stability of high-frequency welding is also the key to the stability of weld quality. Too many impurities and burrs on the edge of the plate will cause instantaneous short-circuit ignition during high-frequency welding, and local cold welding of the weld. To prevent this defect, regular inspections should be made. Whether the installation of the high-frequency coil is reliable, whether the coolant is filtered clean, whether the welding opening angle is appropriate, whether the edge burrs of the coil are removed, and then strengthen the inspection of water pressure and ultrasonic to strictly control the quality of the steel pipe.

The heat treatment process is also one of the influencing factors. Heat treatment generally adopts online intermediate frequency weld heat treatment. The influence of the length of the air-cooled section after intermediate frequency heating on the quality of the weld is easily overlooked. Too high water entry temperature will cause a sharp decline in the impact toughness of the weld. Low, the impact toughness will also decrease, it is necessary to consider the running speed of the production line to determine the length of the air-cooling section.

https://www.steelweldedpipe.com/news/factors-affecting-the-welding-quality-of-erw-welded-pipe-147826.html

Indian Stockist partner visited Xinyue Steel Group

 In April, 2019, our Indian partner visited Tianjin Xinyue Steel Group. He is a local stockist and dealer in India. This visit is to conduct product inspection on the newly signed orders in late March and early April, and to negotiate new orders at the same time.

After receiving the first inquiry from the customer, we soon provided the customer with a competitive price and communicated with the customer by phone to confirm the details of the product requirements. The customer signed the contract with us on the third day and paid the deposit.

Later, we communicated with the customer several times, and the customer placed a new order in early April again. In this factory inspection, the product inspected is ERW welded pipe, the specification is 219*8.18mm*5.8 meters. The customer inspects the dimensions and measures the outer diameter, wall thickness and length. At the same time he is also give the affirmation for the pipe ends and black painting, the customer said he is very satisfied with this order.

After the factory inspection, the customer had an interview with our group CEO in our office. After confirming with us all the details of our previous order, He immediately placed another order of 100 tons of the same specification. At the meeting, the customer said that more and more orders will be signed with the Xinyue group in the future .

No matter what large or small of the order and the complexity of the product, as long as we can help customers to solve the problem, Xinyue Steel Group team will serve customers with a professional attitude.

As the famous pipeline suppliers from China, Xinyue’s goal is to serve for the global market and build the world getting better, warmly welcome to send us inquiry at any time.

http://www.tjxysteel.com/news/Indian-Stockist-partner-visited-Xinyue-Steel-Group-835.html

Common problems and solutions of deburring electric welded pipes

 　　Common problems in the removal process of internal burrs include eccentric, deep, shallow, etc., which of them will affect the quality of weld detection and reduce the yield of welded pipes. In particular, the internal burr is deeply scraped and the wall thickness of the weld is up to If the requirements are not met, the bearing capacity is insufficient here. In severe cases, the welded pipe may burst. The methods for removing burrs in ERW welded pipes are generally divided into two types: online and offline. The on-line removal method is to use the inner burr trimming blade on the inner burr trolley on the traction rod to carry out, and use the relative movement of the tool to plan off the burrs.

　　1. Internal burrs shaved biased

　　When the internal burrs are shaved very biased, there will be steps on the inner wall of the welded pipe at the weld, and the online flaw detection of the weld will alarm and affect the weld quality of the welded pipe. The reason for the internal burr is that the internal burr on the drawbar is scraped from the internal burr on the trolley. The center line of the blade does not coincide with the center line of the burr in the welded pipe, resulting in deviation. Through the inspection of the welded pipe opening, it can be found that the internal burr removed is obviously scraped. The internal burr blade has scratched the base material. Check the position of the tow bar, adjust the position of the tow bar to ensure that the mechanical connection of the tow bar is good, so as to ensure that the tow bar will not shake during work, which will affect the quality of the internal burr. It is also necessary to check whether the internal burr trolley on the tow bar is Place it in the correct working position and check whether the blade screws on the inner burr trolley are loose.

　　2. Internal burr shaved deep

　　When the internal burr is scraped deeply, the wall thickness of the weld will not meet the requirements, resulting in insufficient pressure-bearing capacity, and in severe cases, the pipe may burst.

　　Through the inspection of the physical burr, it is found that the inner burr is too deep, and part of the substrate has been scraped off. When the inner burr blade is working, its working height is relatively high to the inner wall of the welded pipe. If the height of the inner burr blade does not meet the requirements, it will cause Deep inner burr scraping or shallow scraping, at this time, you need to adjust the working height of the inner burr blade to ensure that its height is within the standard range. In addition, check the fasteners on the inner burr trolley to ensure that they are tightly fitted to avoid Loose when working.

　　3. Shallow shaving of internal burrs

　　When the inner burr is shallow, it will cause the inner burr to protrude, which will seriously hinder the transportation of oil and gas. In addition, the inner burr will seriously affect the inspection quality of the weld. The fastening screw of the burr blade to ensure that it will not deviate from the correct working position due to uneven force during work, and the fixing seat of the traction rod needs to be checked to ensure that the traction rod will not be caused by looseness during work In the process of shaving internal burrs, the traction rod is not in the correct working position due to the force.

　　When the internal burr is shallow, since it can no longer be removed online, it needs to be removed offline by the internal burr removal device. After the offline internal burr removal is completed, offline inspection is required to ensure the quality of the weld. In addition, if the offline inspection is not Qualified, further manual inspection of the weld is required to ensure the quality of the weld and avoid the unqualified welded pipe due to the quality of the weld.

　　When removing internal burrs of ERW welded pipe(astm a53 erw), there are mainly problems such as offset, deep scraping, shallow scraping, etc. Each problem will affect the weld quality of the welded pipe. Therefore, in the production process of welded pipe, it is necessary to pay attention to removing the internal burr to ensure that it is removed. The subsequent internal burr meets the standard.

　　http://www.xysteelpipe.com/info/Common-problems-and-solutions-of-deburring-electric-welded-pipes-1983-1.htm