hot-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.

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29/07/2026

TISCO's Nickel-Based Alloys are Making a Strong Mark in the Global Market, Establishing a High-End International Brand

From qualification access to the delivery of N08825, TISCO responded to the "extreme requirements" with "extreme manufacturing".

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16/06/2026

Launch meeting for the mandatory national standard on ‘Hot-rolled H-section steel for building structures’ held in Beijing

Work has officially commenced on drafting China’s first mandatory national standard for hot-rolled H-section steel used in building structures. The standard aims to establish a robust foundation for quality and safety.

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02/06/2026

Bengang Achieves Large-Scale Production of Ultra-Wide and Ultra-Thick Hot-Rolled Plates

Since the beginning of this year, Bengang has broken through the production barriers of conventional hot rolling mills, achieving large-scale mass production of ultra-wide and ultra-thick hot-rolled plates with widths of 2000-2190mm and thicknesses of 20-28mm.

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06/05/2026

Shandong Steel Successfully Develops 216 Single-Tooth Track Steel

Recently, Shandong Steel's newly customized 216 single-tooth track steel, developed for a leading domestic construction machinery company.

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29/04/2026

Malaysian Dong Steel's Hot-Rolled Coils Successfully Passed the EPD Audit

Recently, the hot-rolled coil products of Donggang Malaysia, an overseas subsidiary of Jianlong Group, successfully passed the rigorous audit of the Italian ICMQ organization EPDItaly©.

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13/04/2026

JISCO's Q355C hot-rolled coil has entered the supply chain of major national water conservancy projects.

JISCO, together with companies involved in the Qinghai-Tibet Pipeline Project, secured an order for 4,000 tons of Q355C hot-rolled coils for the western route of the South-to-North Water Diversion Project.

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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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