UNS S31803 vs. UNS S32205 Stainless Steel: The Differences

What is UNS S31803 material?
UNS S31803 is a widely used duplex stainless steel, also known as alloy 2205, renowned for its high strength (approximately twice that of 304/316 stainless steel) and excellent resistance to corrosion, pitting, and stress corrosion cracking. It is ideally suited for harsh chemical, marine, and oil and gas environments, and is a cost-effective alternative to high-nickel alloys.

 

What is UNS S32205 material grade?
UNS S32205 is a popular Duplex 2205 stainless steel, a nitrogen-enhanced alloy known for its excellent strength and superior corrosion resistance, especially against pitting and cracking in chloride environments, making it a common choice over austenitic steels like 316L in demanding chemical, oil & gas, and paper industries, offering cost and weight savings due to its high strength.

 

Are UNS S31803 and UNS S32205 stainless steels similar?

Yes, UNS S31803 and UNS S32205 stainless steels are very similar; both are 2205 duplex stainless steels. However, S32205 is essentially a higher-specification version of S31803, with alloy element (chromium, molybdenum, nitrogen) content at the upper end of the S31803 specification range, resulting in slightly enhanced corrosion resistance and strength. S32205 can often be certified to the S31803 standard as well, making them almost interchangeable.

 

UNS S31803 vs. UNS S32205 Stainless Steel: Composition

Grade		C	Mn	Si	P	S	Cr	Mo	Ni	N
2205 (S31803)	Min Max	- 0.030	- 2.00	- 1.00	- 0.030	- 0.020	21.0 23.0	2.5 3.5	4.5 6.5	0.08 0.20
2205 (S32205)	Min Max	- 0.030	- 2.00	- 1.00	- 0.030	- 0.020	22.0 23.0	3.0 3.5	4.5 6.5	0.14 0.20

 

UNS S31803 vs. UNS S32205 Stainless Steel: Mechanical Properties

Grade	Tensile Str (MPa) min	Yield Strength 0.2% Proof (MPa) min	Elongation (% in 50mm) min	Hardness
				Rockwell C (HR C)	Brinell (HB)
UNS S31803 / UNS S32205	621	448	25	31 max	293 max

 

UNS S31803 vs. UNS S32205：Physical Properties

Grade	Density (kg/m3)	Elastic Modulus (GPa)	Mean Co-eff of Thermal Expansion (μm/m/°C)			Thermal Conductivity (W/m.K)		Specific Heat 0-100°C ( J/kg.K)	Electrical Resistivity (nΩ.m)
			0-100°C	0-315°C	0-538°C	at 100°C	at 500°C
UNS S31803 / UNS S32205	7800	190	13.7	14.2	-	19	-	418	850

 

UNS S31803 stainless steel equivalent materials

Grade	UNS No	Old British		Euronorm		Swedish SS	Japanese JIS
		BS	En	No	Name
2205	S31803 / S32205	318S13	-	1.4462	X2CrNiMoN22-5-3	2377	SUS 329J3L

 

What is the difference between S31803 and S32750?

S31803 (Duplex 2205) is a standard duplex stainless steel, while S32750 (Super Duplex 2507) is a higher-alloyed super duplex grade, differing mainly in composition (S32750 has more Chromium, Molybdenum, Nitrogen), giving S32750 significantly higher strength and superior resistance to pitting and crevice corrosion, making it suitable for harsher environments than S31803.  

 

What are the differences between UNS S32205 and S32750?
UNS S32205 (Duplex Stainless Steel 2205) and UNS S32750 (Super Duplex Stainless Steel 2507) are both duplex stainless steels, but S32750 is a higher-alloyed "super duplex" steel with significantly higher chromium content (approximately 25% compared to 22%), molybdenum, and nitrogen content. Therefore, it exhibits higher strength and better resistance to pitting corrosion and chloride stress corrosion cracking (CSCC) in extreme corrosive environments such as seawater and corrosive chemical processing.

 

If you have project requirements for UNS S31803 stainless steel pipes, we welcome your order. GNEE has a large inventory of popular products for you to choose from. Available in both seamless and welded forms, please contact our factory immediately for detailed chemical composition information and free samples. We offer competitive prices and excellent service.
The pipes are packaged with waterproof paper and steel straps, meeting standard export sea freight packaging requirements, suitable for various transportation methods, or customized according to customer requirements.

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