Product Description
Chemical Analysis
Typical Values (Weight %)
| Carbon | Chromium | Nickel | Molybdenum | Nitrogen | Others |
|---|---|---|---|---|---|
| 0.020 | 23 | 4 | 0.2 | 0.1 | S=0.001 |
| PREN = [Cr%] = 3.3 [Mo%] = 16 [N%] ≥ 24 | |||||
Mechanical Properties
Tensile Properties (Minimum Values)
| °C | Rp 0.2 MPa | Rp 1.0 MPa | Rp 1.0 MPa | °F | YS 0.2% Offset KSI | YS 0.1% Offset KSI | UTS KSI | Elongation % |
|---|---|---|---|---|---|---|---|---|
| 20 | 400 | 440 | 600 | 68 | 58 | 64 | 87 | 25 |
| 100 | 330 | 365 | 570 | 212 | 48 | 53 | 83 | 25 |
| 200 | 280 | 310 | 530 | 392 | 41 | 45 | 77 | 20 |
| 300 | 230 | 260 | 490 | 572 | 33 | 38 | 71 | 20 |
Values obtained for hot rolled plates (th ≤ 2"). Alloy 2304 must not be used for a long time at temperatures higher than 300°C (572°F), where precipitation hardening phenomenon occurs.
Toughness Values (KCV Minimum Values)
| Temp. | -50°C | +20°C | -60°F | +70°F |
|---|---|---|---|---|
| Single | 75 J/cm_ | 90 J/cm_ | 54 ft. lbs | 65 ft. lbs |
| Average (5) | 90 J/cm_ | 150 J/cm | 65 ft. lbs | 87 ft. lbs |
Hardness (Typical Values)
| Average (5) | HV10 180-230 | HB : 180-230 | HRC _ 20 |
Physical Properties
Density : 7,800 kg/m3 - 0.28 lb/in3
| Interval Temper °C | Thermal expansion ax10M-bK-1 | °C | Resistivity (μ_ cm) | Thermal conductivity (W.m-1.K-1) | Specific heat (J.kg-1.K-1 | Young modulus E (GPa) | Shear modulus G (GPa) |
|---|---|---|---|---|---|---|---|
| 20-100 | 13 | 20 | 80 | 17 | 450 | 200 | 75 |
| 20-100 | 13 | 100 | 92 | 18 | 500 | 190 | 73 |
| 20-200 | 13.5 | 200 | 100 | 19 | 530 | 180 | 70 |
| 20-300 | 14 | 300 | 105 | 20 | 560 | 170 | 67 |
Structure
The chemical analysis of 2304 is optimized to obtain a typical 50 a / 50 g microstructure after solution annealing treatment at 950°/1050°C (1742°/1922°F).
The microstructure of 2304 duplex is very stable compared to molybdenum-containing duplex stainless steels. Intermetallic phases are present only after 10 hours holding time in the 750°/850°C (1382°/1562°F) temperature range. Copper additions to 2304 grade, when specified, increase the hardness of the steel after heat treatment in the 350°/500°C (662°/932°F) temperature range.
Processing
Hot Forming
Hot forming must be performed in the 1150/900°C (2100/1650°F) temperature range. After forming, a new solution annealing treatment is recommended in the 950°/1050°C (2100°/1650°F) temperature range to fully restore corrosion resistance properties and mechanical properties. Parts formed with 2304 must be supported carefully during heating to avoid creep deformation.
Cold Forming
Alloy 2304 may be cold formed without any problem. The same equipment as used for the cold forming of 304L and 316L grades can be used. Due to its higher mechanical properties, including the yield strength, higher stresses are required for cold forming. A final solution annealing heat treatment is also recommended after cold forming in order to restore the mechanical and corrosion resistance properties, as decribed in 'hot forming.'
Descaling
Use the same solutions and pastes as for Alloys 304L/316L. The pickling time will be higher than for austenitic grades due to the corrosion resistance properties of the alloy.
Machinability
Alloy 2304 duplex exhibits improved machinability properties particularly when considering drilling. Its behavior is equivalent to that of 316LEZ*. Furthermore, 2304 has better corrosion resistance and cleanliness properties as no sulphur additions are necessary. Localized corrosion resistance behavior is improved.
