cold-rolled Articles

20/10/2026

Masteel Holly Industrial Co., Ltd. is Actively Building a "Second Growth Curve"

Inside the factory of a new materials company located in Bowang District, Ma'anshan City, rolls of gleaming high-performance aluminum coils were about to be shipped to all parts of the country.

Read More
11/08/2026

Shougang Construction's TOSYALI Phase V Cold-Rolled Galvanizing Project in Algeria has Entered the Single-Unit Trial Operation Phase

The Algeria TOSYALI Phase V cold rolling and galvanizing project, undertaken by the Shougang branch, is progressing smoothly.

Read More
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).

Read More
25/08/2025

Pangang Group Vanadium Plate Plant Successfully Completes Trial Rolling of Cold-Rolled Checkered Plate

The Pangang Group Vanadium Plate Rolling Plant has successfully conducted the first trial rolling of cold-rolled patterned plates, achieving a significant breakthrough in diversifying products and establishing a presence in the high-end market.

Read More
19/08/2025

Jilin Jianlong Exports Non-oriented Silicon Steel to Pakistan

Jilin Jianlong recently successfully shipped its first order of 200 tons of non-oriented silicon steel (Grade 50JW800) to Pakistan. The steel will be used in the production of fan motor components.

Read More
09/05/2025

Pangang Successfully Rolled Out 0.5mm Cold-Rolled Thin Titanium Plate

The successful development of 0.5mm cold-rolled thin titanium plate not only meets the domestic market demand for high-end titanium materials, but also polishes Pangang’s “titanium metal business card”.

Read More
10/09/2024

Jingang Pickling Coil Plates are Launched

The launch of new products of Jingang pickling coils represents the inexhaustible motivation of Jingang Holding Group to deepen product research and development.

Read More

Page 1 of 2

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.


Timely Info	Independent	Platform	Multiple guarantees	Self-operated storage

About us	Channel	Useful tools
About China Steel Market	Prices	Steel Weight Calculation
Contact Us	Answers	Why Choose Us
Terms & Conditions	Inventory	Avoiding Trade Fraud Guide
Privacy Policy	Help

cold-rolled Articles

Categories

Answers