-: Stainless Steel :-

Stainless Steel Composition Chart

Stainless Steel Chemical Composition Requirements

Stainless Steel Grade	C	Si	Mn	P	S	Cr	Ni	Mo	Nb
304	≤0.08	≤1.00	≤2.00	≤0.045	≤0.030	18.0-20.0	8.0-10.5	-	-
304L	≤0.03	≤1.00	≤2.00	≤0.045	≤0.030	18.0-20.0	8.0-12.0	-	-
309	≤0.20	≤1.00	≤2.00	≤0.045	≤0.030	22.0-24.0	12.0-15.0	-	-
309H	≤0.08	≤1.00	≤2.00	≤0.045	≤0.030	22.0-24.0	12.0-15.0	-	-
310	≤0.25	≤1.50	≤2.00	≤0.045	≤0.030	24.0-26.0	19.0-22.0	-	-
316	≤0.08	≤1.00	≤2.00	≤0.045	≤0.030	16.0-18.0	10.0-14.0	2.0-3.0	-
316L	≤0.03	≤1.00	≤2.00	≤0.045	≤0.030	16.0-18.0	10.0-14.0	2.0-3.0	-
316N	≤0.08	≤1.00	≤2.00	≤0.045	≤0.030	16.0-18.0	10.0-14.0	2.0-3.0	-
317	≤0.08	≤1.00	≤2.00	≤0.045	≤0.030	18.0-20.0	11.0-15.0	3.0-4.0	-
317L	≤0.03	≤1.00	≤2.00	≤0.045	≤0.030	18.0-20.0	11.0-15.0	3.0-4.0	-
321	≤0.08	≤1.00	≤2.00	≤0.045	≤0.030	17.0-19.0	9.0-12.0	-	-
347	≤0.08	≤1.00	≤2.00	≤0.045	≤0.030	17.0-19.0	9.0-13.0	-	0.60-1.0
410	≤0.15	≤1.00	≤1.00	≤0.040	≤0.030	11.5-13.5	-	-	-
430	≤0.12	≤1.00	≤1.00	≤0.040	≤0.030	16.0-18.0	-	-	-
17-4PH	≤0.07	≤1.00	≤1.00	≤0.040	≤0.030	15.0-17.5	3.0-5.0	-	0.15-0.45
254SMO	≤0.02	≤0.80	≤1.00	≤0.030	≤0.010	19.5-20.5	17.5-18.5	6.0-6.5	-

Introduction to Stainless Steel

Stainless steel is a versatile metal alloy known for its corrosion resistance. It's primarily composed of iron and carbon, with a minimum of 10.5% chromium. This chromium content is crucial for its rust-resistant properties, making it ideal for various applications.

Types of Stainless Steel

1. Austenitic
2. Ferritic
3. Martensitic
4. Duplex
5. Precipitation Hardening (PH)

Austenitic Stainless Steel

• Characteristics: High corrosion resistance, non-magnetic (generally can be magnetic after cold working), good weldability, & excellent ductility.
• Examples: 304, 316, 321
• Common Uses: Kitchenware, chemical equipment, food processing, architectural applications.
• Note: Grade 304 is the most versatile and widely used, while 316 offers superior corrosion resistance, especially in chloride-containing environments.

Ferritic Stainless Steel

• Characteristics: Good corrosion resistance, magnetic, and generally lower cost than austenitic grades.
• Examples: 430, 409, 439
• Common Uses: Automotive trim, appliances, some architectural applications.

Martensitic Stainless Steel

• Characteristics: High hardness and strength, but lower corrosion resistance as compared to austenitic & ferritic grades.
• Examples: 410, 420
• Common Uses: Cutlery, surgical instruments, high strength parts.

Duplex Stainless Steel

• Characteristics: Combine properties of both austenitic & ferritic stainless steels, offering high strength & excellent corrosion resistance, especially against chloride stress corrosion cracking.
• Examples: 2205
• Common Uses: Desalination plants, chemical tanks, offshore structures.

Precipitation Hardening (PH)

• Characteristics: High stress and hardness achieved through heat treatment processes, offering a good balance of strength and corrosion resistance.
• Examples: 17-4PH (S17400)
• Common Uses: Aerospace, medical & high strength applications.