Coil Articles

13/10/2026

Shanxi Jianlong Successfully Developed Ultra-Thick Paint Film Color Coated Steel Plate

Recently, the 40μm thick fluorocarbon coated steel sheet with a front surface, developed and produced by Shanxi Jianlong's 1500mm color-coated steel sheet production line, has been successfully applied to the building envelope system of a key project.

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01/06/2026

JISCO Hongyu New Materials has successfully achieved stable rolling of 2.5mm-thick titanium coils

JISCO Hongyu New Materials, leveraging its CSP and hot continuous rolling lines, has successfully achieved stable rolling of 2.5mm-thick titanium coils and completed the validation of the steel-titanium co-rolling process.

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26/03/2026

Pangang Group successfully produced its first TC4 titanium alloy coil.

Pangang Group Company Limited has successfully produced its first TC4 titanium alloy hot-rolled coil, achieving a breakthrough in the mass production of high-end titanium materials. The product will be mainly used in the 3C equipment field.

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14/01/2026

Jilin Jianlong's Non-Oriented Electrical Steel Achieves Full Grade and Full Specification Coverage

Recently, Jilin Jianlong achieved a milestone breakthrough in the field of high-end non-oriented electrical steel, successfully overcoming the challenge of producing a 0.15mm ultra-thin high-grade product (15JWV1000).

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07/01/2026

Xingtai Iron and Steel's large-coil rolling mill successfully completes its first hot-rolling operation.

Xingtai Iron and Steel's relocation project achieved the first successful hot rolling of large-coil production lines, marking a key advancement in its transformation and upgrading toward high-end special steel using China's first domestically developed green short-process technology. This milestone will serve as a model for regional industrial clusters and high-quality development within the sector.

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23/10/2025

Jingye High-quality Steel Technology Successfully Trial-produced 0.20-0.25mm Ultra-thin Hard Rolled Coils

Recently, Jingye Group Technology Research Center, in collaboration with Gaopin Steel Technology Co., Ltd., successfully completed the trial production of 0.20-0.25mm ultra-thin hard rolled coils.

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18/09/2025

Baosteel Terminals Issues First Order of H-Beam and Coil Steel to be Shipped to Foreign Vessel

Recently, as the foreign ship "Oriental Ace" slowly left the port, Ma Steel Co., Ltd. successfully completed the loading and shipment of the largest batch of H-beams exported from Baosteel Terminal in Baoshan Base, marking the successful completion of the multi-base coordinated export mission.

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Answers

Causes of Common Production Problems in Q235 Spiral Pipes
Common Defects and Causes of Spiral Steel Pipes: Loosening, bubbles, shrinkage cavities, residues, non-metallic inclusions, segregation, white spots, cracks, and various abnormal fracture defects in spiral steel pipes.
Causes of Segregation in Q235 Spiral Pipes: During casting and solidification, selective crystallization and diffusion can cause the aggregation of certain elements, leading to uneven chemical composition. Depending on the distribution location, this can be classified as ingot segregation, center segregation, and point segregation.
Causes of porosity in Q235 spiral tubes: During hot working, gaps are created by the solidification shrinkage of low-melting-point materials and the release of gas, preventing the steel from being welded. Based on their basic distribution, porosity can be divided into two types: centrally located type and generally loose type.
Can galvanized pipes be painted?
You can paint them, but not directly.
Since galvanized pipes have a smooth surface and a highly reactive zinc coating, they must first be cleaned and sanded, then coated with a specialized primer (such as epoxy zinc yellow primer or zinc phosphate primer), followed by a compatible topcoat (such as epoxy paint, polyurethane paint, or water-based acrylic paint). At the same time, avoid using ordinary latex paint, paints containing copper pigments, and alkyd paints, as these can cause peeling, flaking, or accelerated corrosion.
What are the common coating processes for anti-corrosive spiral steel pipes?
The coating scheme for anti-corrosive spiral steel pipes is determined by the operating environment.
The three-layer polyethylene (3PE) coating system combines epoxy powder, an adhesive layer, and a polyethylene layer to form a structurally stable protective barrier.
Epoxy coal tar coating involves the alternating application of epoxy coal tar paint and glass fiber cloth, creating a water- and corrosion-resistant coating system. Internal cement mortar lining forms a smooth inner surface on the pipe wall, helping to reduce flow resistance.
Epoxy powder coating utilizes high-density polyethylene as a base material, balancing mechanical strength with corrosion resistance. Each process has its own specific advantages; the appropriate method should be selected based on the conveyed medium and installation conditions.


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