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Key Differences between SAW (LSAW, SSAW) and ERW Pipe

  From manufacturing processes we can know that SAW (LSAW, SSAW) and ERW pipes are entirely different right from formation, welding etc. and hence, the performance of both the pipes differ in the following aspects:   1. The surface quality of ERW pipes are better when compared to SAW (LSAW, SSAW) pipes, as they are smooth and have a better finish. In most of the SAW pipes, it is mainly about the weld reinforcement internally and externally.   2. The residual stress ratio in ERW is lower than SAW pipes. As ERW pipe deformation happens more in ERW followed by a sizing of flat oval, it results in elliptical vertical changes and necking, thereby making the stress smaller. The displacement of ERW pipes was smaller when compared along the axial and transverse incisions for comparison with SAW pipes built using the same material and it was also easy to detect.   3. The defects found in ERW pipes are lesser than SAW pipes. As there is a solvent deposit in SAW pipes, it results in more de...

Classification of welded steel pipes

  Welded steel pipe, also known as welded pipe, it is made of steel sheet or strip that experience crimp forming welding. The production technology of welded steel pipe is simple, with high production efficiency, various specifications, less equipment investment, but the general strength is lower than the seamless steel pipe.   Since the 1930s, with the rapid development of high quality strip steel rolling production and the progress of welding and inspection technology, the weld quality constantly improves. Welded steel pipe specifications increase day by day, and replace seamless steel pipe in more and more field. In terms of the form of welded steel pipe, it can be divided into the weld seam welded pipe and spiral welded pipe.   The billet that welded steel pipe adopted is steel plate or strip steel. Because of the different welding process, welded steel pipe is divided into furnace welded pipe, welded (erw) pipe and automatic arc welding pipe. Due to its different welding form,...

Spiral Steel Surface Cracking Reason Analysis

  Generally speaking, hydraulic (pneumatic) part in planning the use of mechanical performance, data are assumed to be uniform, successive, isotropic, according to the analysis of this approach is safe and that the plan will sometimes spiral steel pipe unexpected trouble cracking attack.   Study found that the use of brittle cracking and also member of the relevant temperature. After discussions we found that when the temperature drops below a certain temperature, brittle materials will change the situation, the impact absorbed energy decreased, this representation is called cold crisp, high-strength metal resources guessed low stress brittle episodes cracking process, the data arrangement is far from uniform, isotropic. Arrangements have cracks, there will be inclusions, porosity and other drawbacks can be funded look into guessed microcracks. Therefore, even when the program based on the operating temperature of the member to choose a suitable cold brittle temperature change infor...

Spiral Welded Pipe Production and Use

   SSAW steel pipe often there will be some quality problems in the production and use, affecting normal use in some aspects, the need for spiral welded pipe to identify the quality, according to a certain way and performance testing, can produce significant in actual use role, then how to identify counterfeit spiral welded pipe method: the appearance often pockmarked face phenomenon. Generally the whole proportionate amount would be better, mainly taking into account the cumulative error and probability theory this problem. Some of the above please add if inadequate, we welcome the discussion of knowledge about aspects of the steel pipe together, advances constantly exchange. Pock is due to badly worn groove spiral welded pipe surface irregularities caused by uneven defects. Because of shoddy spiral welded pipe manufacturers have to pursue profits, rolling groove most often exceeded. The surface is easy to produce scarring.   Quality spiral welded pipe of uniform composition. High ...

How to Detect the Quality of Spiral Steel Pipe

   Spiral pipe factory should be done before the mechanical performance test and flattening test, and flaring test, and to achieve the standard requirements. Spiral steel pipe quality inspection method is as follows:   1, From the face of it, that is visual inspection. Visual inspection of welded joints is a simple procedure but widely used test method is an important part of product testing, the main defects and deviations are found on the surface of the weld size. Usually by the naked eye, with the standard model, gauge and test tools such as a magnifying glass. If the weld surface defects, weld defects there may be internal.   2, Physical test methods: physical test method is to use some physical phenomena assay or test method. Or within the workpiece material defect inspection, and are generally used NDT methods. NDT ultrasonic flaw detection, radiation detection, penetration testing, magnetic testing and so on.   3, Pressure vessels strength test: pressure vessels, in addit...

The definition and manufacture of seamless steel tube

   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.   Usage   1. there are many types of Construction: pipeline transportation, floor covering, floor water heating, and hot water transportation.   2. processing, bearing sleeve, processing machine parts and so on.   3. electrical types: gas pipeline, water pipeline.   4. wind power plant antistatic tube.   There are many ways to produce smls pipe. According...

Steel billet production process

  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.   Steel billet production process is following:   First, through the steel casting system of continuous casting equipment, directly from the molten steel into steel billet;   Second, the steelmaking system for the production of steel ingots or continuous casting slits through the rolling system of steel processing equipment out of semi-finished products;   Third, the steel production system of steel ingots through the forging equipment processing semi-finished products.