Welded steel pipe corrosion performance

When Ni is contained in the T-shaped welded steel pipe, the corrosion resistance is strong in an acidic environment. In an environment containing sulfuric acid or hydrochloric acid, the higher the Ni content in the T-shaped welded steel pipe, the stronger the corrosion resistance. Under normal circumstances, it is only necessary to add Cr to the T-shaped welded steel pipe to prevent erosion. Poor edge condition of the steel strip is another important cause of wrong edges. The effect of changes in mass flow rate, heat flux density and structural parameters (the ratio of spiral curvature diameter to T-welded steel pipe diameter Dc / D) on the saturated bubble boiling heat transfer coefficient in the vertical spiral tube.

During the production of T-shaped welded steel pipes, the wrong side occurs from time to time, and its influencing factors are many. In the production practice, the steel pipe is often degraded due to the excessive deviation of the wrong side. Therefore, it is necessary to analyze the causes and preventive measures of spiral steel pipe wrong edges.

Due to the poor shape and dimensional accuracy of the head and tail of the uncut steel belt, it is easy to cause the steel belt to be hardly bent during docking and cause wrong edges. Simulation parameter range: vertical pipe: pipe diameter D = lOmm, pipe length L = 660mm; three vertical T-shaped welded steel pipes: pipe diameter D = 10mm, the change in the ratio of the curvature diameter of the T-shaped welded steel pipe to the spiral pipe diameter is Dc / D = 15, 20, 25, spiral pitch Pt = 20mm, tube length L = 503mm, L = 660mm, L = 817MM. Mass flow G = 200 ~ 400Kg / (m’2 · s), heat flux density q = 5 ~ 15KW / m’2, saturation pressure p, saturation = 0.414880MPa, saturation temperature T, saturation = 283.15K.