Stainless Steel 304L (UNS S30400)

SPECIFICATIONS: GRADE 304 / 304L | UNS S30400 / 30403 | ASTM/ASME A240 | Werkstoff 1.4301 / 07

304L is one of the most widely used and versatile stainless steel pipes, Stainless Steel Pipe Fittings and Stainless Steel Flanges at wilsonpipeline Pipe Industry Co., Limited is certified to 304/304L. We are a supplier who can provide stainless steel 304L from stock in sheet, plate, or bar direct from our warehouse and distribute it meeting all cutting and profiling requirements across the world.

This stainless steel grade is found in a variety of commercial sectors, particularly in the chemical industry. It is a sort after material for use in severely corrosive conditions, it is used in heavy gauge components for improved weldability, weld annealing is only necessary in applications where stress loads are excessive.

304L Stainless Steel is characterised by:

1. Basic corrosion resistance

2. Resistance against intergranular corrosion

3. High ductility

Technical information:

Stainless steel 304L is an 18Cr-9Ni austenitic stainless steel. The grade contains small amount of ferrite (≈ 3%) after solution annealing (1000-1100°C – 1832-2012°F) and water quenching.

This kind of steel is one of the basic grades of the stainless steels range. Its low carbon content ensures better ductility and avoids the intergranular corrosion, even on welded pieces without ulterior water quenching.

Stainless steel 304L exhibits austenitic microstructures free of deleterious carbide precipitations at grain boundaries.Typical values (weight %)CCrNIMoNOthers0.02018.59.2–0.05–PREN (%Cr+3.3%Mo+16%N) ≥ 18

Nickel content may be modified to be conform to 1.4306 grade.Tensile properties after water quenching°C°FMinimum guaranteed values *Typical valuesEl %Y.S. 0.2%Y.S. 1%UTSY.S. 0.2%Y.S. 1%UTSMPaKsiMPaKsiMPaKsiMPaKsiMPaKsiMPaKsi20682002924035520/ 65075/ 952653830544570834510021214721181264106024034280404807040200392115171472136052220322403444063353005721001512719340501702519027420623540075289131161733048150221652440058305009328112109163204713020145213805630

* Following EN 10088 hot rolled plates – The EN guaranteed values are valid for a thickness from 5-75mm. Mechanical properties are related to the thickness of the plate.Impact values: KCV ≥ 120 j/cm² (room temperature)°C-196-20+20θ (°C)200400600°F-321-468θ (°F)3927521112KCV (J/cm²) Minimum125160180Ageing H265257252KCV (J/cm²) Typical220250250KCU (J/cm²) Transverse158142122

Typical values

High toughness values at -269°C (-452°F) need specific melts (extra low ferrite content).Interval temper °CThermal expansion αx10-6K-1°C°FResistivity (µΩ cm)Thermal conductivity (W.m-1.K-1)Specific heat (J.kg-1.K-1)Young modulus E (GPa)Shear modulus G (GPa)20-10016206873155002007720-2001710021277165001947520-300172003928417.55201867120-4001830057291195301796820-500184007529720.5540172655009321022254016562Quality corrosion tests guaranteed (special request may be discussed)TESTOther nameCorrosion (1)ResultsASTM A 262 AIntergranularStep or dual structureASTM A 262 BSTREICHERIntergranularNot recommendedASTM A 262 CHUEYIntergranular< 0,6mm/year*ASTM A 262 E DIN 50914STRAUSSIntergranularNo cracking after bendingASTM G48 APittingNot recommended (typical CPT = 5°C-41°F)ASTM G48 BASTM G78CreviceNot recommended (typical CCT ≤ 0°C-32°F)

(1) kind of corrosion mechanism investigated

* Using low ferrite grade.

The alloy is not really resistant to localised corrosion in chloride containing solutions. Pitting may occur even at low temperature (5-10°C – 41-50°F).

The alloy is very prone to stress corrosion cracking in chloride containing solution when temperature is higher than 50°C (122°F).

Stainless steel 304L is corrosion resistant in:

1. Urban media

2. Nitric solution, up to 55% weight, up to 80°C (176°F) (low ferrite)

3. Most of diluted organic acids at moderate temperatures

4. Most of food and pharmaceutical products

5. Pure phosphoric acid
   

6. Whatever concentration in cold solution

7. Up to 10% diluted hot solution sulphuric or fluoridric acid traces increase the corrosion

8. Caustic solutions free of chlorides or fluorides at medium temperatures

The alloys are not corrosion resistant in chloride containing solutions, even diluted, and in sulphuric acid media.

So, the main applications are:

1. Food processing industry (excluding Cl – containing media)

2. Diluted nitric acid solution

3. Nuclear industry (special melts; please consult)