Hoja y placa de acero inoxidable AISI 321

321 stainless steel plates/sheet:

Introduction:

SUS321 stainless steel (UNS S32100) is a stainless steel with very good stability.321 stainless steel is a material with excellent high-temperature stress rupture (Stress Rupture) performance and high-temperature creep resistance (Creep Resistance) stress mechanical properties are superior to 304 stainless steel.

321 Chemical composition: 

Carbon: 0.08 

Silicon: 1.00 

Manganese: 2.00 

Phosphorus: 0.045 

Sulfur: 0.030 

Nickel: 9.00-12.00 

Chromium: 17.00-19.00 

Titanium: 5C-0.70

German grade: X10CrNiTi189

Austenitic stainless steel is equivalent to domestic grade 0Cr18Ni10Ti 　321 stainless steel is Ni-Cr-Mo austenitic stainless steel, its performance is very similar to 304, but because of the addition of titanium metal, it has better resistance to grain boundary corrosion and High temperature strength. Due to the addition of metallic titanium, it effectively controls the formation of chromium carbide.

321 austenitic stainless steel has good corrosion resistance in the atmosphere, and is widely used in petrochemical, electric power, bridge and automobile industries [1]. But the "stainlessness" of stainless steel is not absolute. Due to the special service environment, stainless steel will also corrode. Factors such as medium concentration, pH value, and temperature will have a greater impact on the corrosion resistance of stainless steel. For example, if it is used for a long time in the sensitization temperature range of 450~850℃, the intergranular corrosion of stainless steel will occur. The mechanism is that C combines with Cr at the grain boundary to form Cr23C6 and precipitate, which reduces the Cr content at the grain boundary. This is called "chromium-depleted". The Cr element is one of the main elements that inhibit intergranular corrosion. When the Cr content at the grain boundary is less than 12%, the chance of intergranular corrosion will increase.

Industry application:

Used in outdoor open-air machines that require high chemical, coal, and petroleum industries to resist grain boundary corrosion, heat-resistant parts for building materials, and parts with difficult heat treatment

1. Petroleum waste gas combustion pipeline

2. Engine exhaust pipe

3. Boiler shell, heat exchanger, heating furnace parts

4. Silencer parts for diesel engines

5. Boiler and pressure vessel

6. Chemical truck

7. Expansion joint

8. Spiral welded pipes for furnace pipes and dryers

Physical properties:

The physical properties of alloys 321 and 347 are quite similar, in fact, they can be regarded as the same. The values listed in the table apply to both alloys.

If properly annealed, alloys 321 and 347 stainless steel mainly contain austenite and titanium carbide or niobium carbide. A small amount of ferrite may or may not appear in the microstructure. If exposed to temperatures between 1000°F-1500°F (593°C-816°C) for a long time, a small amount of sigma phase may form.

Heat treatment cannot harden the stable alloys 321 and 347 stainless steel.

In addition to the thermal conductivity of the metal, the total heat transfer coefficient of the metal also depends on other factors. In most cases, the film heat dissipation coefficient, rust and metal surface conditions. Stainless steel can keep the surface clean, so its heat transfer is better than other metals with higher thermal conductivity.

Permeability

The stable alloys 321 and 347 are generally not magnetic. In the annealed state, its magnetic permeability is lower than 1.02. Permeability will change due to composition and increase due to cold work. The permeability of welds containing ferrite will be higher.