L245 pipeline steel Professional steel manufacturer

Eddy current detection of Changsha pipeline is only applicable to conductive materials. If non-conductive materials are used, vortex shaped current cannot be induced and eddy current cannot be used for detection. Eddy current testing is especially suitable for surface and near surface testing of conductive materials. Eddy current testing does not require couplings. The electromagnetic field excited in eddy current testing is essentially an electromagnetic wave with wave and particle characteristics, so the probe (coil) and workpiece can be transmitted without coupling, so non-contact detection can be carried out. This is better than ultrasonic detection. Because the ultrasonic wave of the low pressure boiler tube is a mechanical wave, it can only travel through the material. Therefore, ultrasonic detection must be coupled between the probe and the workpiece. Eddy current testing can achieve rapid and automatic testing. Eddy current testing can be suitable for the detection of high temperature metals because of their electrical conductivity at high temperatures. Changsha pipeline flow detection is also suitable for the detection of special-shaped materials, as long as the coil is made into various shapes. Commonly used to pipe material have brinell, rockwell, Vickers hardness 3 kinds. Changsha pipeline "Seamless steel pipe for Low and medium pressure Boiler". There are 43 kinds of changsha pipeline specifications for all kinds of boiler structures, with diameters of 10 ~ 426mm. There are 29 kinds of wall thickness from 1.5 mm to 26mm. However, the outer diameter and wall thickness of superheated steam pipe, large smoke pipe, small smoke pipe and arch brick pipe used in locomotive boiler are stipulated otherwise. The outer diameter of changsha pipeline is 22 ~ 530mm, and the wall thickness is 20 ~ 70mm. Cold drawn (cold rolled) tube diameter 10 ~ 108mm, wall thickness 2.0 ~ 13.0mm. Appearance quality: cracks, folding, rolling, scarring, separation and wrinkles are not allowed on the inner and outer surface of the steel pipe. These defects should be eliminated completely. The clearance depth shall not exceed the negative deviation of the nominal wall thickness, and the actual wall thickness at the clearance shall not be less than the minimum allowable wall thickness. The key is to adopt different methods according to different situations, such as adopting adiabatic and refractory materials to block the flame from burning the steel structure directly, reducing the speed of heat transfer and delaying the time of temperature rise and strength weakening of the steel structure. But whatever the approach, the principle is the same. Fireproof coating is a kind of more advanced fireproof technology measures at present. Because of the influence of impurity elements on the quality of Changsha pipeline pipe, high-level products have very strict requirements on the control of harmful elements and inclusions in Changsha pipeline pipe. It is necessary to control the content of various impurity elements at a very low level as far as possible, and the refining process outside the furnace is often used in production to ensure its cleanliness. General boiler tube temperature is below 350℃, domestic pipe is mainly made of no. 10, 20 carbon bonded steel Changsha pipe or cold drawn pipe.