AISI316L Large Diameter stainless steel tube pipe Tolerance D4 / T3 Heat Resistance

AISI316L Large Diameter stainless steel tube pipe Tolerance D4 / T3 Heat Resistance

Alloy 316/316L is molybdenum-bearing austenitic stainless steel. The higher nickel and molybdenum content in this grade allows it to demonstrate better overall corrosion resistant properties than 304, especially with regard to pitting and crevice corrosion in chloride environments. In addition, Alloy 316/ 316L provides excellent elevated temperature tensile, creep and stress-rupture strengths, as well as outstanding formability and weldability. 316L is the lower carbon version of 316 and is immune from sensitization; therefore, it is very frequently used in heavy gauge welded components.

Specifications: UNS S31600 / S31603

Applications:

Food preparation equipment, especially in chloride environments

Chemical processing, equipment

Laboratory benches and equipment

Rubber, plastics, pulp & paper machinery

Pollution control equipment

Boat fittings, value and pump trim

Heat exchangers

Pharmaceutical and textile industries

Condensers, evaporators and tanks

Standards:

ASTM/ASME: UNS S31600 / S31603

EURONORM: X1 CrNiMo 17 12 2 / X3 CrNiMo 17 12 2

AFNOR: Z 6 CND 17-11 / Z 2 CND 17-12

DIN: 1.4401 / 1.4404

Stainless steel types 1.4401 and 1.4404 are also known as grades 316 and 316L respectively. Grade 316 is an austenitic grade second only to 304 in commercial importance.

316 stainless steel contains an addition of molybdenum that gives it improved corrosion resistance. This is particularly apparent for pitting and crevice corrosion in chloride environments.

316L, the low carbon version of 316 stainless steel, is immune to grain boundary carbide precipitation (sensitisation). This makes it suited to use in heavy gauge (over about 6mm) welded components.

For elevated temperature applications the high carbon variant, 316H stainless steel and the stabilised grade 316Ti stainless steel should be employed.

The austenitic structure of 316 stainless steel gives excellent toughness, even at cryogenic temperatures.

Corrosion Resistance

Grade 316 has excellent corrosion resistance when exposed to a range of corrosive environments and media. It is usually regarded as “marine grade” stainless steel but is not resistant to warm sea water. Warm chloride environments can cause pitting and crevice corrosion. Grade 316 is also subject to stress corrosion cracking above around 60°C.

Heat Resistance

316 has good resistance to oxidation in intermittent service to 870°C and in continuous service to 925°C. However, continuous use at 425-860°C is not recommended if corrosion resistance in water is required. In this instance 316L is recommended due to its resistance to carbide precipitation.

Where high strength is required at temperatures above 500°C, grade 316H is recommended.

Fabrication

Fabrication of all stainless steels should be done only with tools dedicated to stainless steel materials. Tooling and work surfaces must be thoroughly cleaned before use. These precautions are necessary to avoid cross contamination of stainless steel by easily corroded metals that may discolour the surface of the fabricated product.

Chemical Composition:

Spec: EN 10088-3:2005

1.4404 Steel