DSAW pipe can be specified in very large diameter and to exact inside or outside dimensions.

When welding long cracks and surfacing layer, it is necessary to weld from one end to the other end. During welding, the weld and surfacing layer are in hot state, which can reduce the shrinkage of the weld and reduce the internal stress. When knocking, the effect is better when the welding metal temperature is 800 ℃. If the temperature drops, the knocking force will also be reduced. If the temperature is too low, it is not allowed to knock around 300 ℃ to avoid cracks, The principle of forging method is basically the same as above, but the difference is that the weldment should be heated before hammering.

What is welding crack? Welding crack is a common serious defect in welding parts. Under the brittle factors such as welding stress, the bonding force of metal atoms in the local area of the welding joint is damaged, resulting in the gap caused by the new interface. Its characteristics are sharp gap and large aspect ratio. The crack affects the safe use of the welding parts. It is a very dangerous process defect. The welding crack has a certain incubation period, Some are produced during reheating after welding.

The weld can maintain high strength, exceeding the strength required by the welding material code and application. In many cases, this weld strength can not be identified by the welding material code itself.

Continuous casting method, also known as heat-type continuous casting method. Absolutely prevent melt-type wall nucleation, the mold is heated to a temperature above the solidification of the melt. Solidification of the melt from the mold only at the moment will be. With the continuous slab leaving the crystallizer, along the direction of the solidification of the melt in the heat flow in the opposite direction but it is heated to a temperature above the metal to be cast above the liquidus temperature, performed. T

As the name implies, the main constituents of welded steel pipe is steel and carbon. Because of to the composition of these pipes, they are nicely suited for commercial and geothermal applications due to the reality of the tensile power they offer. These pipes are seamless and for that reason confirm to be of outstanding electricity as essential oil pipelines or as transporters of other fluids.

Technologies for Production of Seamless & ERW Pipes “CPE” Technology” used for Seamless Pipes& Tubes Production up to 7-inches OD is the world renowned Technology. “Plug Mill” Technology used for Higher Dia. Seamless Pipes & Tubes Production from 7-inches to 14-inches,is the most reliable technology,in higher dia. Segment. High frequency Induction Welding Technology is used for ERW Pipes &Tubes upto 21-inchesOD.

Classification of welded joints Welded joints is constituted by weld fusion zone, heat affected zone and its adjacent base metal. Welded joints is mainly from two aspects, one is connected to the role, another is power transmission.

Welded steel pipe for fire fighting means for fire safety, fire-fighting equipment, transport fire extinguishing water, gas pipeline or other media material. As the fire pipeline is normally in a quiescent state, and more stringent requirements for the pipeline, the pipeline needs to pressure resistance, corrosion resistance, high temperature performance. his pipe use less time and frequency, working pressure is bigger.

Carbon steel is steel in which the main interstitial alloying constituent is carbon in the range of 0.12–2.0%. The American Iron and Steel Institute (AISI) definition says:

The main defects that may appear in the process of submerged arc welding are not only insufficient penetration, burn through and poor forming, but also porosity, crack and slag inclusion. This paper mainly introduces the causes and preventive measures of porosity and slag inclusion.

In the process of high-frequency induction welding, especially in the production of products with thick wall and small diameter, such as small pipes of 1 inch and below, the wall thickness is relatively thick. Generally, we will encounter a particularly wide heat affected zone at the weld, exceeding 1 / 3 of the pipe diameter arc surface, or even 1 / 2 of the pipe diameter arc surface. If the pipe diameter is small, the whole pipe will even turn red, It will adversely affect the final welding performance requirements of some products, and even lead to waste products.