Q235B Q345B hot rolled steel pipe medium and heavy stainless steel welded pipe​

400 Series - Ferritic and Martensitic Stainless Steels

408—Good heat resistance, weak corrosion resistance, 11% Cr, 8% Ni.

409 - The cheapest model (British and American), usually used as a car exhaust pipe, is a ferritic stainless steel (chromium steel).

410—Martensitic (high-strength chromium steel), with good wear resistance and poor corrosion resistance.

416 - The addition of sulfur improves the processing properties of the material.

420 - "cutting grade" martensitic steel, the earliest stainless steel similar to Brinell high chromium steel. Also used in surgical knives, can do very bright.

430—ferritic stainless steel, used for decoration, such as for car accessories. Good formability, but poor temperature and corrosion resistance.

440—High-strength cutting tool steel, with slightly higher carbon content, high yield strength can be obtained after proper heat treatment, and the hardness can reach 58HRC, which is one of the hardest stainless steels. The most common application example is "razor blades". There are three commonly used models: 440A, 440B, 440C, and 440F (easy to process).

500 Series - Heat Resistant Chromium Alloy Steel.

600 Series—Martensitic precipitation hardening stainless steels.

630—The most commonly used type of precipitation hardening stainless steel, usually also called 17-4; 17%Cr, 4%Ni.