Galvanized welded pipe production process

Galvanized welded pipes are widely used in various industries due to their strength, durability, and excellent corrosion resistance provided by a protective zinc coating. The production process of galvanized welded pipes involves several precise and well-coordinated steps that ensure the pipes meet high quality standards and perform reliably under different conditions. Here is a detailed look at each stage of the process.

Production Steps of Galvanized Welded Pipes

Round Steel Preparation:

The process begins with the selection and preparation of high-quality round steel billets or coils, which serve as the raw material for the pipe. This ensures a solid foundation for the rest of the production process.

Heating:

The prepared round steel is then heated in a furnace to a specific temperature. This heating softens the steel, making it easier to shape and perforate in subsequent steps.

Hot Rolling and Perforation:

Once heated, the steel undergoes hot rolling to achieve the desired thickness and diameter. At the same time, perforation is conducted to create a hollow structure within the steel, laying the foundation for the formation of the pipe.

Cutting off the Head:

After hot rolling and perforation, the head of the pipe is cut off to remove any irregularities and ensure a uniform shape.

Pickling:

The pipe is then subjected to an acid pickling process. This step removes oxides and surface impurities, leaving a clean and smooth surface ready for further processing.

Grinding:

Grinding follows pickling to refine the pipe surface, removing any remaining rough patches or minor imperfections.

Lubrication:

Before the cold rolling process, a layer of lubricant is applied to reduce friction, facilitate shaping, and ensure a smooth finish on the pipe’s surface.

Cold Rolling Processing:

In this step, the pipe undergoes cold rolling, which further refines its shape, thickness, and surface quality. Cold rolling enhances dimensional precision and surface smoothness, resulting in a high-quality product.

Skimming:

Any residual lubricants or other surface impurities are removed through skimming, preparing the pipe for subsequent heat treatment.

Solution Heat Treatment:

Solution heat treatment is applied to enhance the pipe’s mechanical properties, including strength and toughness. This heat treatment also ensures that the pipe’s structure is uniform and meets the required standards for durability.

Straightening:

After heat treatment, the pipe is straightened to correct any slight deformations that may have occurred during earlier stages, ensuring the final product is dimensionally accurate and stable.

Cutting to Length:

The pipes are then cut to the required lengths, depending on customer specifications and the intended application.

Pickling (Final Cleaning):

A final pickling step is conducted to clean the surface thoroughly and prepare it for galvanizing. This ensures that the zinc coating will adhere properly and provide long-lasting corrosion resistance.

Galvanizing (Protective Zinc Coating):

In this stage, the pipe is immersed in a bath of molten zinc, which coats the surface and provides a durable, corrosion-resistant layer. This galvanizing process enhances the pipe’s resistance to rust and weathering.

Product Testing:

The final step in the production process involves rigorous testing to ensure each pipe meets quality standards. Tests may include dimensional checks, pressure testing, and inspections of the zinc coating to ensure uniformity and thickness.

The meticulous process involved in producing galvanized welded pipes ensures that the final product is robust, corrosion-resistant, and suitable for a range of industrial applications, from construction to plumbing and beyond. Through each stage, quality control is maintained to meet the demanding requirements of today’s market.