Stainless Steel Grade 304H includes a high carbon content making the steel more suitable for utilization in applications where high temperatures are available. The benefit of this grade is that it is an austenitic chromium-nickel steel alloy as well as the greater carbon content distribute to increased tensile and yield strength. The material is recommended for utilizing in ASME pressure vessels in working service above 525° C because of the grade's heat resistant properties.
Characteristics304 & 304L have magnificent resistance to corrosive environment, for example textile, chemical and petroleum industries. They are found suitable in dairy and food industries as well as perform exceptionally well in rural and industrial atmospheric exposure.
MachiningTo work harden slow speeds and heavy feeds will minimize this alloy’s tendency. Because of long stringy chips, the utilization of chip breakers is prudent. Many organizations now offer premium machinability grades, for example CarTech with their Project 70 and 7000 series.
WeldingAll fusion and resistance process have been successfully utilized in welding 304. AWS E/ER308 or 312 filler metal is recommended. Many users choose 304L for cleaner and stronger welds which have a controlled low carbon content designed to reduce carbide precipitation at the weld boundaries.
Hot WorkingForging, heading and other hot working should be followed uniform heating to range between 2100-2300 F (1149-1260 C). Fast cooling is necessary to attain maximum corrosion resistance in finished parts.
Cold WorkingPromptly fabricated by most cold working technique, 304 may require intermediate annealing to avoid cracking or tearing from radical deformation. Full annealing ought to be followed any operation to decrease internal stress and optimize corrosion resistance.
Annealing1850-2050 F (1010-1121 C) followed by fast cooling.
HardeningThis alloy doesn’t reply to heat treatment. Cold work will motivate in an increase both hardness and strength.
Chemical Composition %Grade | C | N | Si | P | S | Cr | Mn | Ni | Fe |
304 | 0.08 max | 0.10 max | 0.75 max | 0.045 max | 0.030 max | 18.0 - 20.0 | 2.0 max | 8.0 - 10.5 | Remainder |
304L | 0.03 max | 0.10 max | 0.75 max | 0.045 max | 0.030 max | 18.0 - 20.0 | 2.0 max | 8.0 - 12.0 | Remainder |
304H | 0.04 - 0.10 | 0.10 max | 0.75 max | 0.045 max | 0.030 max | 18.0 - 20.0 | 2.0 max | 8.0 - 10.5 | Remainder |
Grade | Tensile Strength (ksi) | 0.2% Yield Strength (ksi) | Elongation% in 2 inches |
304 | 75 | 30 | 40 |
304L | 70 | 25 | 40 |
304H | 75 | 30 | 40 |
Units | Temperature in °C | |
Density | 8.03 g/cm³ | Room |
Specific Heat | 0.12 Kcal/kg.C | 22° |
Melting Range | 1399 - 1454 °C | - |
Modulus of Elasticity | 193 KN/mm² | 22° |
Electrical Resistivity | 72 µΩ.cm | Room |
Coefficient of Expansion | 16.9 µm/m °C | 20 - 100° |
Thermal Conductivity | 16.2 W/m -°K | 20° |
Pipe / Tube (SMLS) | Sheet / Plate | Bar | Forging | Fitting |
A 213 | A 240, A 666 | A 276 | A 182 | A403 |
Manufacturing |
Refractory Anchors |
Fasteners |
Custom Machining |
Custom Fabrication |
Piping / Spools |
Stamped Parts |
B/W Fittings |
S/W Fittings |
Flanges |
Compression Fittings |
Raw Materials |
Pipes |
Tubes |
Bars |
Sheets |
Plates |