ASTM A790 Free PDF

What is ASTM A790?

ASTM A790 is a standard specification for seamless and weldable ferritic/austenitic stainless steel pipe. ASTM A790 pipes are manufactured using seamless or automated welding processes without the addition of filler metal during welding. Thermal analysis is performed to determine the percentages of specified elements. To meet the specified requirements, tensile tests, hardening tests, flattening tests, hydrostatic tests, and non-destructive electrical tests are required.

 

What is the grade of material for ASTM A789 Duplex Steel?

Standard Item	ASTM A789		ASTM A790		EN 10216-5
Grade	S31803 S32205 S32750		S31803 S32205 S32750		1.4301 1.4307 1.4948 1.4315 1.4401 1.4404 1.4571 1.4541 1.4941 1.4845 1.4449 1.4438 1.4550 1.4912 1.4462 1.4410

 

ASTM A789 Duplex Steel Chemical Composition

UNS
Designation	C	Mn	P	S	Si	Ni	Cr	Mo	N	Cu	Others
S31803	0.030	2.00	0.030	0.020	1.00	4.5–6.5	21.0–23.0	2.5–3.5	0.08–0.20	. . .	. . .
S32205	0.030	2.00	0.030	0.020	1.00	4.5–6.5	22.0–23.0	3.0–3.5	0.14–0.20	. . .	. . .
S32550	0.04	1.50	0.040	0.030	1.00	4.5–6.5	24.0–27.0	2.9–3.9	0.10–0.25	1.50 –2.50	. . .
S32707	0.030	1.50	0.035	0.010	0.50	5.5–9.5	26.0–29.0	4.0–5.0	0.30–0.50	1.0 max	Co 0.5 –2.0
S32750	0.030	1.20	0.035	0.020	0.80	6.0–8.0	24.0–26.0	3.0–5.0	0.24–0.32	0.50	. . .
S32760	0.030	1.00	0.030	0.010	1.00	6.0–8.0	24.0–26.0	3.0–4.0	0.20–0.30	0.50 –1.00	W 0.50 –1.00

A Maximum, unless a range or minimum is indicated. Where ellipses (…) appear in this table, there is no minimum and analysis for the element need not be determined or reported.
B Designation established in accordance with Practice E527 and SAE J1086.
C % Cr + 3.3 × % Mo + 16 × % N $ 41.
D % Cr + 3.3 × % Mo + 16 × % N $ 40.

 

Tensile Strength and Hardness Requirements

Grade	Tensile strength, min., ksi [MPa]	Yield strength, min., ksi [MPa]	Elongation in 2 in., or 50mm, min, %	Hardness, Max Brinell
S31803	90 [620]	65 [450]	25	290
S32205	95 [655]	70 [485]	25	290
S32750	116 [800]	80 [550]	15	310
S32760	109 [750]	80 [550]	25	300
S32950	100 [690]	70 [480]	20	290
S32520	112 [770]	80 [550]	25	310

 

ASTM A789 Duplex Steel O.D. Tolerance

O.D. Tolerance (mm)	O.D.	O.D.Tolerance	O.D.	O.D.Tolerance	O.D. Tolerance Class
	D<12.7	+/-0.13	10.3≤D≤48.3	+0.40/-0.80	D3	+/-0.75% or +/-0.3mm
	12.7≤D<38.1	+/-0.13	48.3<D≤114.3	+0.80/-0.80
					whichever is the greater
	38.1≤D<88.9	+/-0.25	114.3<D≤219.1	+1.60/-0.80	D4	+/-0.5% or +/-0.1mm
	88.9≤D<139.7	+/-0.38	219.1<D≤457.0	+2.40/-0.80
					whichever is the greater

 

ASTM A789 Duplex Steel W.T. Tolerance

W.T. Tolerance (mm)	O.D.	W.T.Tolerance	O.D.	W.T.Tolerance	W.T. Tolerance Class
	D<12.7	+/-15%	10.3≤D≤73.0	+20.0%/-12.5%	T3	+/-10% or +/-0.2mm
	12.7≤D<38.1	+/-10%
			88.9≤D≤457.0 t/D ≤5%	+22.5%/-12.5%	whichever is the greater
	38.1≤D<88.9	+/-10%			T4	+/-7.5% or +/-0.15mm
			88.9≤D≤457.0 t/D >5%	+15.0%/-12.5%
	88.9≤D<139.7	+/-10%
					whichever is the greater

 

Heat Treatment

UNS Designation	Temperature	Quench
S31803	1870-2010 °F [1020-1100°C]	Rapid cooling in air or water
S32205	1870-2010 °F [1020-1100°C]	Rapid cooling in air or water
S31500	1800-1900 °F [980-1040°C]	Rapid cooling in air or water
S32750	1880-2060 °F [1025-1125°C]	Rapid cooling in air or water
S32760	2010-2085 °F [1100-1140°C]	Rapid cooling in air or water
S32950	1820-1880 °F [990-1025°C]	Rapid cooling in water
S32520	1975-2050 °F [1080-1120°C]	Rapid cooling in air or water

 

ASTM A789 Duplex Steel ydrostatic Test

ydrostatic Test	The Hydrostatic Test shall be in accordance with ASTM A1016.Could be replaced by ECT.		The Hydrostatic Test shall be in accordance with ASTM A999.Could be replaced by ECT.		The hydrostatic test shall be carried out at a test pressure of 7MPa or at a test pressure calculated using the following formula P=2St/D S=70%Rp0.2
Intergranular Corrosion Test	Usually use Pitting Corrosion Test.		Usually use Pitting Corrosion Test.		EN ISO 3651-2 (Optional)
Eddy Current Test	Could be replaced by HT.		Could be replaced by HT.		EN 10246-3

 

What is the difference between ASTM A928 and A790?
ASTM A790 specifies the elements and requirements for the manufacture of seamless and welded pipes, while ASTM A928 covers only electric fusion welded pipes. ASTM A790 requires that duplex and super duplex steel pipes be welded without the addition of any filler metal.