Grade grouping
Precipitation hardening stainless steel. Good formability and good weldability, can be used as ultra-high strength materials in the nuclear industry, aviation and aerospace industry applications.
Components can be divided into Cr system (400 series), Cr-Ni system (300 series), Cr - Mn-Ni (200 series), heat-resistant chromium alloy steel (500 series), and precipitation hardening Department (600 series).
200 Series: chrome - manganese - nickel austenitic stainless steel
300 Series: chromium - nickel austenitic stainless steel
301: ductility for forming products. Machining allows them to quickly harden. Good weldability. Abrasion resistance and fatigue strength than 304 stainless steel.
302: corrosion resistance, with 304, because the carbon is relatively high and thus strength better.
303: by adding a small amount of sulfur, phosphorus than 304 easier cutting.
304: the commonly used model, that is, 18/8 stainless steel. GB Grade 06Cr19Ni10.
309: compared to the 304 has better temperature resistance.
316: Following the 304 after the second of the most widely used steel, mainly for the food industry, pharmaceutical industry, and surgical equipment, add molybdenum element to obtain the special structure of an anti-corrosion. And thus has better resistance to chloride corrosion compared with 304 of its for marine steel. SS316 is often used in nuclear fuel recovery. 18/10 stainless steel is usually also in line with the application level.
321: In addition to the added titanium elements to reduce the risk of corrosion of materials, weld, and other properties similar to the 304.
347: Add the stability of niobium, and weldable air appliance parts and chemical equipment.
400 Series: ferritic and martensitic stainless steel.
408: good heat resistance, weak anti-corrosive, 11% Cr, 8% of Ni.
409: the cheapest model (BAR), usually as an automobile exhaust pipe, is a ferritic stainless steel (chrome steel).
410: martensite (high strength chrome steel), good wear resistance, corrosion resistance is poor.
416: Adding sulfur to improve the processing properties of the material.
420: "cutting tool grade martensitic steels, similar to the Brinell high-chromium steel this is the first stainless steel. Also used in surgical tools, can do very bright.
430: ferritic stainless steel, decorative, such as for car accessories. Good formability, heat resistance and corrosion resistance worse.
440: high-strength cutting tool steel, carbon is slightly higher, after appropriate heat treatment to obtain a higher yield strength, hardness can achieve 58HRC, belong to the list of the hardest stainless steel. The most common application example is the "razor blade". There are three commonly used models: 440A, 440B, 440C, in addition to 440F (easy processing).
500 series: heat-resistant chromium alloy steel.
600 Series: martensitic precipitation hardening stainless steel.
630: The most commonly used precipitation hardening stainless steel models, usually, also known as 17-4; 17% Cr, 4% Ni.
Corrosion resistance
When the atomic number of the chromium content in steel of not less than 12.5%, the electrode potential of the steel can be a mutation from negative potential to rise to the positive electrode potential. Prevent electrochemical corrosion.
