Wall Thickness 1.4mm 316 Stainless Steel Square Pipe ISO 9001-2008

Wallthickness 1.4mm High hardness strong strength 316 Stainless Steel Square Pipe

316 stainless steel square tube is not rust resistant, but corrosion resistant. It can be said that different types of steel adapt to different operating conditions

What is the reason for the corrosion resistance of square tube, the corrosion situation that is easy to occur, and how to prevent the corrosion of 316 stainless steel square tube.

The meaning and classification of corrosion resistance of 316 stainless steel square tube

The 316 stainless steel square tube is only corrosion-resistant steel, not rust free in a complete sense, so far no corrosion resistant steel has been invented under any conditions. Therefore the specific steel is to adapt to the specific use of the environment.

Corrosion resistance principle of 316 stainless steel square tube:

① Adding alloying elements such as Cr and Ni can effectively improve the corrosion resistance of steel by increasing the electrode potential of the base metal and reducing the number of microcells.

(2) Adding alloying elements can make the steel obtain single-phase solid solution structure at room temperature, and reduce the number of microcells, thus improving the corrosion resistance of the steel.

(3) The addition of alloy element chromium in the steel makes the surface of the steel form a dense structure, do not dissolve into the corrosive medium, and high resistance of Cr2O3 passivation film, the passivation film structure is dense, stable, thickness of 1-6nm. It is a protective film of metal matrix, and with the increase of chromium content in steel, the thickness and strength of passivation film will increase accordingly.

 

Classification and prevention of 316 stainless steel square tube corrosion

 

1. Pitting

 

Pitting corrosion (as shown in FIG. 1), also known as pitting corrosion and pore corrosion, is one of the common local corrosion of 316 stainless steel square tubes. Generally, the pitting depth is larger than its diameter. When there are some active anions (CI-) in the medium, these anions are adsorbed on some points on the metal surface first, thus damaging the passivation film on the surface of 316 stainless steel square tube. There are defects in steel, impurities and solute the heterogeneity, once the surface passivation membrane damage, on substrate metal surface defect is easy, to assume the activated state, and passivation membrane as the passive state, thus formed the blunt activity - corrosion cell, because the anode area is much smaller than the cathode area, anode current density is very big, the corrosion to the deep development, The metal surface soon corroded into holes.

 

Pitting on SUS304 steel pipe used in brine

 

A way to prevent pitting

 

(1) Selecting pitting resistant materials, adding molybdenum and increasing chromium content in steel, such as 316L steel;

 

② Using reasonable heat treatment system, the 316 stainless steel square tube matrix is in complete solution state;

 

③ Reduce the concentration of halogen ions in the solution and improve the PH value of the solution;

 

(4) stir the solution to avoid local concentration of the solution and prevent impurities from sticking to the surface of the steel;

 

⑤ Improve the surface finish of 316 stainless steel square tube;

 

⑥ Reduce the temperature of the medium;

 

Adopt cathodic protection measures.

Our 316 Stainless Steel Square Pipe Advantage
1.	The purity of the steel strip is high
2	Main materials such as nickel, chromium and copper are up to standard and stable
3	Smooth surface, no peeling, no black spots, no cracks, no strain, smooth weld
4	Not easy to rust, corrosion resistance, stamping bending, high temperature resistance
5	Good extension line, solid welding, in the processing range can be flaring, shrinking, bending, cone cracking
6	Wide scope of application
7	Good sealing
8	Various specifications
9	Save equipment time
10	Immune to inclement weather
11	The tube body (inside and outside) is bright, accurate, high hardness, strong strength and stiffness, and easy to handle on the surface

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