Chemical compositions of stainless steel

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Stainless Steel Composition What I...

Stainless Steel Composition

Stainless steel is a composition of various elements to enhance corrosion resistance of steel. The main alloying component in all stainless steel metals is chromium (10.5% minimum).

The most common type of stainless steel is the austenitic stainless steel which features grades 304 and 316 stainless steels. This range is known for its high resistance to corrosion because of its high chromium content combined with nickel.

Ferritic stainless steel is the second most popular. It includes grade 430 stainless steels. While this range doesn’t match the corrosion resistance of austenitic steels, it’s a cost effective alternative and is often used in the catering industry.

Martensitic steels have low chromium content hence low corrosion resistance but, have high strength. Martensitic steels are ideal for applications that require incredible strength.

Below is a table detailing the chemical composition of some of the stainless steel grades that are supplied by thyssenkrupp Materials (UK).

If the grade that you are looking for isn't present, or, if you need to know any more information, you can either visit our mechanical properties page or our stainless steel data sheets.

All data is to EN110088-2

Maximum values are listed unless otherwise indicated

Austenitic Grades

Grade	EN Specification	Carbon (C)	Silicon (S)	Manganese (Mn)	Phosphorus (P)	Sulfur (S)	Chromium (Cr)	Molybdenum (Mo)	Nickel (Ni)	Nitrogen (N)	Iron (Fe)
301	1.4310	0.05 - 0.15	2.00	2.00	0.045	0.015	16.0 - 19.0	0.80	6.0 - 9.5	0.10	Balance
304	1.4301	0.07	1.00	2.00	0.045	0.015	17.5 - 19.5	-	8.0 - 10.5	0.1	Balance
304L	1.4307	0.03	1.00	2.00	0.045	0.015	17.5 - 19.5	-	8.0 - 10.5	0.1	Balance
201	1.4372	0.15	1.00	5.5 - 7.5	0.045	0.015	16.0 - 18.0	-	3.5 - 5.5	0.05 - 0.25	Balance
316	1.4401	0.07	1.00	2.00	0.045	0.015	16.5 - 18.5	2.0 - 2.5	10.0 - 13.0	0.1	Balance
316L	1.4404	0.03	1.00	2.00	0.045	0.015	16.5 - 18.5	2.0 - 2.5	10.0 - 13.0	0.1	Balance

Austenitic Grades

Grade	EN Specification	Carbon (C)	Silicon (S)	Manganese (Mn)	Phosphorus (P)	Sulfur (S)	Chromium (Cr)	Molybdenum (Mo)	Nickel (Ni)	Nitrogen (N)	Iron (Fe)
301	1.4310	0.05 - 0.15	2.00	2.00	0.045	0.015	16.0 - 19.0	0.80	6.0 - 9.5	0.10	Balance
304	1.4301	0.07	1.00	2.00	0.045	0.015	17.5 - 19.5	-	8.0 - 10.5	0.1	Balance
304L	1.4307	0.03	1.00	2.00	0.045	0.015	17.5 - 19.5	-	8.0 - 10.5	0.1	Balance
201	1.4372	0.15	1.00	5.5 - 7.5	0.045	0.015	16.0 - 18.0	-	3.5 - 5.5	0.05 - 0.25	Balance
316	1.4401	0.07	1.00	2.00	0.045	0.015	16.5 - 18.5	2.0 - 2.5	10.0 - 13.0	0.1	Balance
316L	1.4404	0.03	1.00	2.00	0.045	0.015	16.5 - 18.5	2.0 - 2.5	10.0 - 13.0	0.1	Balance

Ferritic Grades

Grade	EN Specification	Carbon (C)	Silicon (Si)	Manganese (Mn)	Phosphorus (P)	Sulfur (S)	Chromium (Cr)	Titanium (Ti)	Niobium (Nb)	Molybdenum (Mo)	Nickel (Ni)
409	1.4512	0.030	1.00	1.00	0.040	0.015	10.5 - 12.5	[6 x (C + N)] to max 0.65	-	-	-
430	1.4016	0.080	1.00	1.00	0.040	0.015	16.0 - 18.0	-	-	-	-
434	1.4113	0.080	1.00	1.00	0.040	0.015	16.0 - 18.0	-	-	-	-
439	1.4510	0.050	1.00	1.00	0.040	0.015	16.0 - 18.0	[4 x (C + N) + 0.15] to max 0.8	(3 x C + 0.3) to max 1	-	-
4509	1.4509	0.030	1.00	1.00	0.040	0.015	17.5 - 18.5	0.1 - 0.6	-	-	-
436	1.4513	0.025	1.00	1.00	0.040	0.015	16.0 - 18.0	[4 x (C + N) + 0.15] to max 0.8	-	0.80 - 1.40	0.020

Ferritic Grades

Grade	EN Specification	Carbon (C)	Silicon (Si)	Manganese (Mn)	Phosphorus (P)	Sulfur (S)	Chromium (Cr)	Titanium (Ti)	Niobium (Nb)	Molybdenum (Mo)	Nickel (Ni)
409	1.4512	0.030	1.00	1.00	0.040	0.015	10.5 - 12.5	[6 x (C + N)] to max 0.65	-	-	-
430	1.4016	0.080	1.00	1.00	0.040	0.015	16.0 - 18.0	-	-	-	-
434	1.4113	0.080	1.00	1.00	0.040	0.015	16.0 - 18.0	-	-	-	-
439	1.4510	0.050	1.00	1.00	0.040	0.015	16.0 - 18.0	[4 x (C + N) + 0.15] to max 0.8	(3 x C + 0.3) to max 1	-	-
4509	1.4509	0.030	1.00	1.00	0.040	0.015	17.5 - 18.5	0.1 - 0.6	-	-	-
436	1.4513	0.025	1.00	1.00	0.040	0.015	16.0 - 18.0	[4 x (C + N) + 0.15] to max 0.8	-	0.80 - 1.40	0.020

Martensitic Grades

Grade	EN Specification	Carbon (C)	Silicon (S)	Manganese (Mn)	Phosphorus (P)	Sulfur (S)	Chromium (Cr)	Nickel (Ni)	Nitrogen (N)	Iron (Fe)
410	1.4006	0.08 - 0.15	1.00	1.50	0.040	0.015	11.5 - 13.5	0.75	-	Balance
420	1.4021	0.16 - 0.25	1.00	1.50	0.040	0.015	12.0 - 14.0	-	-	Balance
420	1.4031	0.07	1.00	2.00	0.045	0.015	17.5 - 19.5	8.0 - 10.5	0.1	Balance

Martensitic Grades

Grade	EN Specification	Carbon (C)	Silicon (S)	Manganese (Mn)	Phosphorus (P)	Sulfur (S)	Chromium (Cr)	Nickel (Ni)	Nitrogen (N)	Iron (Fe)
410	1.4006	0.08 - 0.15	1.00	1.50	0.040	0.015	11.5 - 13.5	0.75	-	Balance
420	1.4021	0.16 - 0.25	1.00	1.50	0.040	0.015	12.0 - 14.0	-	-	Balance
420	1.4031	0.07	1.00	2.00	0.045	0.015	17.5 - 19.5	8.0 - 10.5	0.1	Balance

What is Stainless Steel?

The term stainless steel refers to a wide variety of grades of metal that contain an alloy that has at least 10.5% of chromium. The most popular grades of stainless steel are 304 and 430. Each of the different grades of stainless steel contains different alloying elements that contribute to its properties such as resistance to corrosion, strength, and flexibility.

Because it’s a low-cost material, has a great appearance, has a high resistance to corrosion, and its durable, stainless steel has become very popular, and a preferred material in different applications.

Why is it Stainless?

The word simply means the metal does not stain. This valuable attribute is a result of the addition of the alloying element chromium which reacts with oxygen in the air forming a layer of chromium oxide which protects the surface of the metal.

If scratches or contact with aggressive chemicals destroy the layer, it repairs itself as soon as the metal is exposed to the air again, forming a constant protective coat on the steel.