Phosphating process for steel pipe

Abstract

The invention discloses a phosphating process for a steel pipe and relates to a treatment process for the steel pipe. The treatment process comprises the following steps: S1, oil and rust removing treatment; S2, washing; S3, phosphating treatment; S4, drying. Each liter of phosphating solution is prepared from the following components in parts by weight: 30 to 40 parts of phosphoric acid, 20 to 25parts of zinc oxide, 0.2 to 0.3 part of sodium chlorate, 0.2 to 0.3 part of sodium molybdate, 0.2 to 0.4 part of m-nitrobenzenesulfonic acid sodium, 0.5 to 1.0 part of phosphating additive, and ammonium hydroxide of which the pH is adjusted to 2.0 to 3.5. The phosphating process disclosed by the invention has the advantages that the phosphating process can be performed at normal temperature by cooperating all the components in a system; and in addition, the phosphating solution does not contain harmful substances such as nitrate, nitrite and heavy metal, and has no pollution to the operationenvironment or no harm to operators.

Description

technical field [0001] The invention relates to a steel pipe treatment process, more specifically, it relates to a steel pipe phosphating process. Background technique [0002] Phosphating is a process in which chemical and electrochemical reactions form a phosphate chemical conversion film, and the formed phosphate conversion film is called a phosphating film. The purpose of phosphating is mainly to provide protection for the base metal and prevent the metal from being corroded to a certain extent; it is used as a primer before painting to improve the adhesion and anti-corrosion ability of the paint film layer. [0003] The Chinese patent with the publication number CN109013704A discloses a seamless steel pipe manufacturing process, which includes the following steps: a. heating; b. perforation; c. pickling treatment: pickling the pipe material with pickling solution; d. Phosphating treatment: In the step of carrying out phosphating treatment on the pipe material after pic...

AI Technical Summary

Problems solved by technology

[0004] In the above technical solution, the phosphating process needs to be carried out under the heating condition of 50-75°C. On the one hand, it consumes a lot of energy, and on the other hand, it leads to a higher temperature in the processing workshop, which makes the working environment of the staff worse. ,Room for improvement

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