ASTM A312 TP316L Welded Pipe
ASTM A312 TP316L Welded Pipe
ASTM A312 TP316L Welded Pipe
ASTM A312 TP316L Welded Pipe

ASTM A312 TP316L Welded Pipe

Welding 316 stainless steel has good welding performance. All standard welding methods can be used for welding. When welding, 316Cb, 316L or 309Cb stainless steel filler rods or welding rods can be used according to the use.

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Product Introduction

Why is the surface of 316L stainless steel pipe corroded?

First, chemical corrosion.

1, surface pollution: oil, dust and acid, alkali, salt attached to the surface of the workpiece are converted into corrosive media under certain conditions, chemical reaction with some components of stainless steel, resulting in chemical corrosion and rust.

2, surface scratches: a variety of scratches on the destruction of passivation film, so that stainless steel protection ability is reduced, easy to react with chemical media, chemical corrosion and rust.

3, cleaning: After pickling passivation cleaning is not clean resulting in residual liquid retention, direct corrosion of stainless steel (chemical corrosion). Second, electrochemical corrosion. 1, carbon steel pollution: scratches caused by contact with carbon steel and corrosion medium form galvanic cells and produce electrochemical corrosion. 2, cutting: cutting slag, splashing and other easy to rust substances attached to the corrosion medium to form a galvanic cell and produce electrochemical corrosion. 3, baking school: the composition of the flame heating area and the metallographic structure change and are not uniform, and the corrosion medium forms a galvanic cell and produces electrochemical corrosion.

4, welding: physical defects in the welding area (biting edge, porosity, cracks, non-fusion, non-welding penetration, etc.) and chemical defects (coarse grain, grain boundary chromium, segregation, etc.) and corrosion medium to form galvanic cells and produce electrochemical corrosion.

5, material: stainless steel chemical defects (non-uniform composition, S, P impurities, etc.) and surface physical defects (loose, sand holes, cracks, etc.) are conducive to the formation of galvanic cells with corrosive media and produce electrochemical corrosion.

6, passivation: pickling passivation effect is not good resulting in stainless steel surface passivation film is uneven or thin, easy to form electrochemical corrosion.

7, cleaning: the residual pickling passivation liquid and stainless steel chemical corrosion products and stainless steel parts to form electrochemical corrosion.

Chemical Composition

SS	316L
Ni	10 - 14
N	0.10 max
Cr	16 – 18
C	0.08 max
Si	0.75 max
Mn	2 max
P	0.045 max
S	0.030 max
Mo	2.00 - 3.00

Mechanical Properties

Grade	316L
Tensile Strength (MPa) min	485
Yield Strength 0.2% Proof (MPa) min	170
Elongation (% in 50mm) min	40
Hardness
Rockwell B (HR B) max	95
Brinell (HB) max	217