Both 20# seamless steel pipe and 20G seamless steel pipe are carbon structural steel with average carbon content of 0.20%. There are big differences in the use standard, chemical composition, mechanical properties and price between A514 grade Q QT steel plate, 20# seamless steel pipe and 20G seamless steel pipe, so they must be selected correctly in the design and use, so as to avoid affecting the service life or even causing destructive accidents. The purpose of A514 grade Q QT steel plate, GB8162 20# seamless steel pipe is for general structure, the purpose of GB8163 20# seamless steel pipe is for conveying fluid, and the purpose of GB3087 standard 20# seamless steel pipe is for low and medium pressure boiler. 20G seamless steel pipe is used for high pressure steam boiler and pipeline.
A514 grade Q QT steel plate surface cracks refer to the linear cracks on the surface of A514 grade Q QT steel plate, which should generally be the same as the forging or rolling direction. Formation reason: it is mainly due to the hairline, hot crack and cold crack caused by surface over burning, decarburization, looseness, deformation and excessive internal stress during processing (forging, rolling, heat treatment, quenching and tempering), as well as the high content of sulfur and phosphorus impurities on the surface. Inspection method: A514 grade Q QT steel plate surface cracks can be detected by naked eye observation, acid pickling, magnetic particle inspection, coloring inspection and metallographic method.
The weldability of A514 grade Q QT steel plate is good. It means that under certain process and construction conditions, A514 grade Q QT steel plate can obtain good performance after welding. Weldability is a measure of the hot workability of steel. Weldability can be divided into weldability in construction and weldability in use. Weldability in construction refers to the sensitivity of cracking in weld metal and near seam zone, and hardening sensitivity of steel in near seam zone. Good weldability means that under certain welding process conditions, the weld metal and steel near the seam do not produce cracks. Weldability in use means that the mechanical properties of weld and HAZ steel are not lower than those of base metal.
The strip steel thickness is generally below 6mm, which is convenient for crimping and processing. You should choose the A514 grade Q QT steel plate, strip steel specifications according to your own purposes. The specifications and materials used for different purposes are different, so you must confirm it before buying. It is best to ask professionals to give advice before purchasing strip steel, and purchase the specifications and types you need according to the corresponding requirements.
