Galvanizing principle of cold drawn seamless pipe

Cold drawn seamless tubing is a seamless pipe with high dimensional accuracy and good surface finish for mechanical structures and hydraulic equipment.

Production process of cold drawn seamless pipe

Round tube billet→heating→piercing→heading→annealing→pickling→oiling (galvanizing)→multi-pass cold drawing (cold rolling)→billet tube→heat treatment→straightening→hydraulic test (flaw detection)→marking→storage.

Basic principle of hot-dip galvanizing in cold drawn seamless pipe processing

1) Basic principles of organic chemistry of hot-dip galvanizing

In the galvanizing tank filled with hot-dip galvanizing solution, the part to be plated after cleaning and special preparation is used as the negative electrode, and the plated metal material is used for anodic oxidation. The two aspects are respectively connected to the positive and negative stages of the DC regulated power supply. The hot-dip galvanizing solution for large-scale cold-drawn seamless pipes is composed of a solution containing chemical substances for plating metal materials, conductive acid salts, buffers, pH regulators, and preservatives. After connecting to the power supply, the metal in the hot-dip galvanizing solution is ionized, and moves to the negative electrode to form a coating under the action of the potential difference. The anodized metal produces metallic ionization and enters the hot-dip galvanizing bath to maintain the concentration of the ionized metal to be plated. During hot-dip galvanizing, the quality of anodizing raw materials, the composition of hot-dip galvanizing solution, temperature, current intensity, power supply time, mixing compressive strength, dissolved residue, switching power supply waveform, etc. all affect the quality of the coating. Manipulation must be carried out in moderation.

2) Basic principle of hot-dip galvanizing process

In a rotating drum with plating, glass marbles, zinc dust, water and vulcanization accelerator. The glass marbles as the impacting material rotate with the drum, and generate friction and impact with the surface of the plated parts to generate mechanical energy. Under the function of organic chemical vulcanization accelerator, the coated zinc powder is "cold welded" to the surface of the plated part to form a smooth, uniform and delicate coating with a certain thickness.

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