Decarburization and Oxidation of Spiral Steel Pipe

When the spiral steel pipe (SSAW) is heated, the iron, alloy, and elements on the surface of the steel react with oxygen, carbon dioxide, and water vapor in the medium to form an oxide film. The phenomenon is called oxidation. The dimensional accuracy and surface brightness of the workpieces deteriorate after oxidation at high temperatures (generally above 570°C), and steel parts with poor hardenability of oxide film are prone to quenching soft spots. Measures to prevent oxidation and reduce decarburization include: coating the workpiece surface, sealing and heating with stainless steel foil packaging, heating with a salt bath furnace, heating with protective atmosphere, such as purified inert gas, controlling the carbon potential in the furnace, and flame burning furnace.

When the spiral steel pipe is heated, the surface carbon reacts with the oxygen, hydrogen, carbon dioxide and water vapor in the medium (or atmosphere), reducing the surface carbon concentration, which is called decarburization. The surface hardness, fatigue strength and The wear resistance is reduced, and the residual tensile stress formed on the surface is likely to cause network cracks on the surface of the steel pipe.

Tips: ASTM A53 Gr.B is the grade in ERW high frequency welded pipe, divided into A and B grades. ASTM is only a set of specifications. ASTM steel pipe A53 A corresponds to the Chinese standard GB8163 raw material is 10# steel, and A53 B corresponds to the Chinese standard GB8163 raw material 20#.
For example: ASTM (standard) A53 (grade) gr is grade (abbreviation of grade) b (grade B)