Type

TRM ref

UNS ref

DIN ref.

Notes

304

S30400

1.4301

Basic18Cr-8%Ni austenitic stainless steel. Does not rust and is useable up to about 800°C without excessive oxidation or loss of strength. Does not embrittle at sub-zero temps. Normally non- magnetic. Contains up tp 0.08% carbon therefore subject to sensitisation and ‘weld decay’ - corrosion after heating to about 650°C as would usually occur in the heat affected zone adjacent to a weld

304L

S30403

1.4306

Same as 304 except that carbon is reduced to under 0.03% max., therefore is immune to sensitisation and weld decay.

321

S32100

1.4541

Similar to 304 (18%Cr-10%Ni) but with Titanium added as a stabiliser.

Titanium prevents sensitisation & weld decay. 321 loses stabilising additive (Ti) during welding.

347

S34700

1.4550

Similar to 321 but with Niobium (2 x the amount of titanium) added as a stabiliser. Better transfer of stabilising addition (Nb) in 347 than in 321 during welding.

UK favours the use of 321 whereas USA favours 347.

No difference in performance and both are slightly inferior to 304L.

316

S31600

1.4401

Similar to 304 (17%Cr-9%Ni) with the addition of 3% molybdenum. Suitable for wet, corrosive applications (sea water) as it is more resistant to local and general corrosion than 304 and 321/347.

It’s performance on hot, dry applications is slightly inferior to 304L.

316L

S31608

1.4404/1.4432

Same as 316 but with a lower concentration of carbon. 316L is immune to sensitisation. It has better weld properties but lower strength at high temperatures than 316

316Ti

S31603

1.4571

316Ti is resistant to weld decay similarly to 316L but loses stabilising additive (Ti) during welding.

310

S31000

1.4841

25% Cr-20% Ni stainless steel. Strong and resistive to oxidation up to about 1100 °C otherwise similar to 304L. Essentially a high temperature material but not specified for wet conditions.

310S

S31008

1.4845

As 310 but with lower carbon content Not subject to weld decay

446

S44600

1.4762

25% Cr ferritic stainless steel. Good resistance to sulphur bearing atmospheres at elevated temperatures and molten metals Not suitable for low-medium range temperatures (350-800°C)

Inconel 600

N06600

2.4816

Nickel-chromium-iron alloy with very good oxidation resistance and strength at high temperatures (up to 1150 °C).

Do not use in sulphur atmospheres higher than 550 °C (use 310 instead).

Inconel 601

N06601

2.4851

Nickel-chromium-iron alloy with addition of aluminium. Very good oxidation resistance and strength at high temperatures (up to 1250 °C).

Do not use in sulphur atmospheres higher than 550 °C (use 310 instead).

Incoloy 825

N08825

2.4858

Nickel-chromium-iron alloy. Very good corrosion resistance in both oxidising and reducing media at temperatures up to 540°C.

Cupronickel 70/30

CN107

C 71500

2.0882

Copper - Nickel alloy with additions of Iron and Manganese

Good resistance to aqueous and seawater corrosion, pitting and crevice corrosion in quiet sea water, chloride and sulphide stress corrosion cracking and impingement corrosion. Fair resistance to biofouling.

Subject to galvanic corrosion in contact with stainless steel and nickel based alloys

Working temperature limited by 400°C