Stainless steel has a series of characteristics such as excellent corrosion resistance, formability and toughness in a wide temperature range, so it has been widely used in heavy industry, light industry, daily necessities industry and building decoration industries. Different stainless steel varieties are very important.
In stainless steel, two opposing forces operate simultaneously: ferrite forming elements continue to form ferrite, and austenite forming elements continue to form austenite. The final crystal structure depends on the relative amounts of the two types of additive elements. Chromium is a ferrite forming element, so chromium in the formation of stainless steel crystal structure and the austenite forming element is a competitive relationship. Because iron and chromium are ferritic forming elements, the 400 series stainless steels are fully ferritic stainless steels with magnetic properties. In the process of adding the austenite forming element nickel to fe-Cr stainless steel, with the increase of nickel composition, the formation of austenite will gradually increase, until all the ferrite structure is transformed into austenite structure, thus forming 300 series stainless steel.
300 series stainless steel is an alloy material containing iron, carbon, nickel and chromium. It is a non-magnetic stainless steel material with better malleability than 400 series stainless steel. Due to the austenitic structure of 300 series stainless steel, it has strong corrosion resistance in many environments, excellent resistance to fracture caused by corrosion caused by metal overstress, and its material properties are not affected by thermal treatment.
321 austenitic stainless steel has good corrosion resistance in the atmosphere, and is widely used in petrochemical, electric power, bridge and automobile industries.
But the stainless steel "rust" is not absolute, because of the special service environment, stainless steel will also occur corrosion.
Medium concentration, pH value, temperature and other factors will have a greater impact on the corrosion resistance of stainless steel.
For example, in the range of 450~850℃ sensitization temperature long-term use, stainless steel will occur intergranular corrosion.
The mechanism is that C combines with Cr at grain boundary to form Cr23C6 and precipitates out, which reduces Cr content at grain boundary, which is the so-called "poor chromium".
The Cr element is one of the main elements to inhibit the intergranular corrosion. When the Cr content at the grain boundary is less than 12%, the probability of intergranular corrosion will increase.
Equivalent Grades
| Grade |
Euronorm |
China GB |
Japanese JIS |
| No. |
| 321 |
1.4541 |
0Cr18Ni10Ti |
SUS321 |
Standard Specification
| Types of stainless steel pipes |
round pipe,squard pipe ,rectangular pipe,oval tube,and pipe in roll. |
| pipe thickness |
0.2-200mm |
| out diameter |
3mm，6mm,10mm,12mm,60mm,80mm,102mm,180mm,245mm,530mm,630mm etc. |
| type of the pipe |
weld pipe and sealess pipe. |
| length |
1000mm,3000mm,5800mm,6000mm,12000mm ,and any length you want,etc. |
| surface |
Hot rolled (HR), Cold rolled Tube (CR), 2B, 2D, BA NO(8), SATIN (Met with Plastic Coated) |
Composition content
| Grade |
C |
Mn |
Si |
P |
S |
Cr |
Mo |
Ni |
N |
| 321 |
Min.
Max. |
≤0.08 |
≤2.00 |
≤0.75 |
≤0.045 |
≤0.03 |
17.0～19.0 |
/ |
9.0～19.0 |
/ |
Yield strength/Mpa: ≥177
Tensile strength /MPa: ≥480(hardness HB≤187)
Elongation /% : ≥40
Section shrinkage ψ(%) : ≥60
Hardness: 187 hb or less;
90 HRB or less;
200 hv or less
Density: 7.98g/cm3;
Characteristic machining technology
1D -- The surface has discontinuous granular shape, also known as fog surface.
Processing technology: hot rolling + annealing shot peening pickling + cold rolling + annealing pickling.
2D - A slightly silvery white colour.
Processing technology: hot rolling + annealing shot peening pickling + cold rolling + annealing pickling.
2B -- Silver white with better gloss and flatness than a 2D surface.
Processing technology: hot rolling + annealing shot peening pickling + cold rolling + annealing pickling + quenching and tempering rolling.
Ba - Excellent surface gloss, high reflectivity, like a mirror surface.
Processing technology: hot rolling + annealing shot peening pickling + cold rolling + annealing pickling + surface polishing + quenching and tempering rolling.
No.3 -- Good gloss, coarse grain surface.
Processing technology: polishing and tempering rolling for 2D or 2B with 100~120 abrasive materials (JIS R6002).
No.4 -- Good gloss, fine lines on the surface.
Processing process: polishing and tempering rolling for 2D or 2B with 150~180 abrasive materials (JIS R6002).
HL -- Silver grey with hair streaks.
Processing technology: 2D products or 2B products with appropriate granularity of abrasive materials for polishing the surface is a continuous abrasive grain.
MIRRO -- Specular.
Processing technology: 2D products or 2B products with appropriate granularity of the grinding material grinding and polishing to the mirror effect.
Price List
| Stainless Steel 321pipe Price List |
FOB Shanghai Per Unit (USD) |
| 321 stainless steel Round pipe |
$3700.00-$3900.00 |
| 321mirror Stainless Steel pipe |
$3900.00-$4100.00 |
| 321Stainless Steel Black pipe |
$3800.00-$4000.00 |
| 321Stainless Steel Square pipe |
$3700.00-$3900.00 |
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