+86-400-1866-598 cs@chinasteelmarket.com +86-18864881658 (Whatsapp&Wechat)
Login | Register
Empowering small and medium-scale steel purchasing
Quickly obtain FOB/CIF price
Home > Articles

Articles

Short News
09/09 17:36
< Welded Steel Pipe, size: DN100(4"*3.75mm), grade: Q235(ASTM A36 Gr.D), brand: YOUFA. Tianjin - Gangrui reduction by --26.24 tons
09/09 17:34
< Cold Rolled Stainless Steel Sheet, size: 1.0*1219*2438, grade: 316L/2B(316L/2B), brand: YONGJIN. Guangzhou - Yuefa increased by 32.01 tons
09/09 17:33
< Rebar, size: Φ30, grade: HRB500E(ASTM A615 Grade 75), brand: SHAGANG. Shanghai - Caoan reduction by --99.70 tons
09/09 17:31
< Cold Rolled Steel Plate, size: 2.0*1250*2500, grade: SPCC(ASTM A1008 CS), brand: LIUGANG. Tangshan - Lunan reduction by --24.30 tons
09/09 17:30
< Galvalume Steel Sheet & Coil, size: 1.0*1250*C, grade: DX51D+AZ120(ASTM A792/A792M CS), brand: PANGANG. Guangzhou - Yuefa reduction by --16.04 tons
09/09 17:29
< H-beam, size: 900*300*16*28, grade: Q235B(ASTM A36), brand: JINXI. Tangshan - Lunan reduction by --10.93 tons

Answers

  • What are the advantages and disadvantages of cold-rolled steel plates and hot-rolled steel plates?

    Advantages of Hot-Rolled Steel Plate: Hot-rolled steel can effectively eliminate defects, such as grain refinement. Furthermore, bubbles and cracks generated during casting can be treated at high temperatures and then welded together, avoiding these issues.

    Disadvantages of Hot-Rolled Steel Plate: After hot rolling, any non-metallic materials within the steel are compressed into thin sheets, causing delamination, which can affect quality and cause unnecessary problems.

    Advantages of Cold-Rolled Steel Plate: It allows for greater deformation of the steel, raising its yield point. Furthermore, the forming speed is relatively fast, resulting in higher production yields without damaging the coating.

    Disadvantages of Cold-Rolled Steel Plate: During the forming process, stresses are generated in the cross-section, causing changes in the steel's properties. Furthermore, the wall thickness of cold-rolled steel is relatively small, and subsequent processing does not increase the thickness, resulting in a reduced load-bearing capacity.


  • What are the requirements and limitations in the use of duplex stainless steel?

    The continuous operating temperature range of duplex stainless steel is -50°C to 250°C. The lower limit is determined by the brittle transition temperature of the stainless steel, while the upper limit is determined by the brittle transition temperature of 475°C. The upper limit temperature must not exceed 300°C.

    Duplex stainless steel needs to be cooled quickly after solution treatment. Slow cooling will cause the precipitation of brittle phases, thereby reducing toughness and local corrosion resistance of the steel.

    Proficiently master the welding rules of duplex stainless steel. The safe use of duplex stainless steel equipment is closely related to the correct mastery of welding technology. Some equipment failures are usually related to welding.

    In order to ensure the best overall performance, the phase ratios in duplex stainless steels need to be controlled. If the two-phase ratio is out of balance, single-phase ferrite is easily formed in the weld heat-affected zone (HAZ), which may lead to stress corrosion cracking sensitivity in certain media.


  • Why does stainless steel rust at room temperature?

    Stainless steel is rust-resistant. Its rust resistance and corrosion resistance are due to a passive film on its surface, which prevents the metal from being corroded by external media, thus providing its rust resistance. When stainless steel is exposed to moisture or chloride ions, or during mechanical wear or welding, the passive film is destroyed, causing the stainless steel to rust. Therefore, the rust resistance and corrosion resistance of stainless steel are relative. Different environments require stainless steel with different chromium contents.


    Although stainless steel is a highly corrosion-resistant decorative metal material, its surface can still rust under certain harsh conditions.

    The corrosion resistance of stainless steel is closely related to its chromium content. Its main components are iron, chromium, and nickel, with a chromium content of at least 10.5%. At room temperature, oxygen in the air reacts with chromium to form a dense protective chromium oxide film. This film blocks further attack from external oxygen, water, and acid ions, protecting the stainless steel substrate from corrosion. However, if this film is damaged or other factors prevent it from forming or persisting for a long time, the stainless steel loses its rust resistance and becomes more susceptible to rust.


Timely Info Independent Platform Multiple guarantees Self-operated storage

China Steel Market

Empowering small and medium-scale steel purchasing


How can I help you?