Super duplex 2507 Round Bars

Super duplex 2507 hot rolled round bar is a chloride resistant duplex bar turned into seawater pump shafts, valve parts and bolting.

16 to 125 mm Duplex stainless steel Made to order

HOT ROLLED ROUND BARS

Super duplex 2507 hot rolled round bar

Super duplex 2507 hot rolled round bar is bar of UNS S32750, also written F53 and EN 1.4410, rolled from 16 to 125 mm diameter. The structure is about half ferrite and half austenite, which makes the bar magnetic and gives it roughly twice the strength of 304 or 316. It carries more chromium, molybdenum and nitrogen than 2205, and those three elements set the pitting resistance equivalent number, a figure calculated from the analysis that ranks a grade against pitting in chloride water. For S32750 the composition limits put that figure above 40. The grade is therefore specified in place of 2205 where seawater, brine or sour well fluid attacks a 22 percent chromium duplex bar.

The bar is supplied solution annealed and water quenched, the treatment that takes the alloying elements into solution and holds the balance of the two phases. It is not hardenable by heat treatment, so the strength comes from the structure. ASTM A479 sets a minimum yield of 550 MPa for solution annealed S32750 bar, against 205 MPa for annealed 304 under ASTM A276. That strength slows machining, and welding needs a controlled heat input with an over alloyed filler so the weld keeps enough austenite. Service stops near 300 degrees Celsius, above which brittle phases form. Bar of this grade is turned into seawater pump and valve shafts, desalination and offshore parts, subsea bolting, and flanges the customer forges. Laxcon Steels rolls the bar to order.

Composition limits in weight percent are carbon 0.03 maximum, manganese 1.2 maximum, sulphur 0.02 maximum, phosphorus 0.035 maximum, silicon 0.8 maximum, chromium 24.0 to 26.0, nickel 6.0 to 8.0, molybdenum 3.0 to 5.0, nitrogen 0.24 to 0.32 and copper 0.5 maximum.

SPECIFICATION

Super duplex 2507 hot rolled round bar supply conditions

Size range: 16 mm - 125 mm (5/8" - 5")
Length: Up to 8 metres
Tolerances: ASTM A484, EN10060
Heat treatment: Solution annealing and water quenching
Grade: 2507 / S32750 / F53 (2507, S32750, F53, 1.4410)
Family: Duplex stainless steel
Supply: Made to order in this grade; every published size of the form

Composition of Super duplex 2507

Element	Symbol	Minimum %	Maximum %
Carbon	C		0.03
Manganese	Mn		1.2
Sulphur	S		0.02
Phosphorus	P		0.035
Silicon	Si		0.8
Chromium	Cr	24.0	26.0
Nickel	Ni	6.0	8.0
Molybdenum	Mo	3.0	5.0
Nitrogen	N	0.24	0.32
Copper	Cu		0.5

Composition, weight percent, balance iron. From the Laxcon Steels grade reference.

Equivalents of Super duplex 2507

Standard	Designation
UNS	S32750
EN number	1.4410

Equivalence means nearest counterpart, not identity: each standards body sets its own composition window, so the limits of the standard named on the order govern.

Pitting resistance

The pitting resistance equivalent number of Super duplex 2507 runs from 37.7 at the specified minimum chromium, molybdenum and nitrogen to 47.6 at the maxima, computed as PREN = Cr + 3.3Mo + 16N (International Molybdenum Association). It ranks resistance to chloride pitting against other austenitic and duplex grades and nothing else: it does not predict crevice corrosion, stress corrosion cracking or service life. The pitting resistance reference carries the full table.

Governing standards

EN 10088-3: Stainless steels: technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products for general purposes. Composition, heat treatment condition and mechanical properties per grade.
EN 10060: Hot rolled round steel bars for general purposes: dimensions and tolerances on shape and dimensions.
ASTM A276/A276M: Stainless steel bars and shapes: composition, condition, mechanical properties and finish designations for hot-finished and cold-finished bar.
ASTM A484/A484M: General requirements for stainless steel bars, billets and forgings: permissible variations in dimensions, straightness, weight and length, and the test and marking requirements every bar order inherits.
ASTM A479/A479M: Stainless steel bars and shapes for use in boilers and other pressure vessels: the bar specification a pressure-part drawing calls for.
ASTM A314: Stainless steel billets and bars for forging.
NACE MR0175 / ISO 15156: Materials for use in H2S-containing environments in oil and gas production: the sour-service limits on hardness and condition.
ASTM A182/A182M: Forged or rolled alloy and stainless steel pipe flanges, forged fittings, valves and parts for high-temperature service: the F51 and F53 duplex forging grades.
EN 10204: Metallic products, types of inspection documents: the 2.2 test report and the 3.1 and 3.2 inspection certificates a purchase order can call for.

Weight per metre

Diameter (mm)	kg per metre	Metres per tonne
16	1.59	629.5
17	1.79	557.6
18	2.01	497.4
19	2.24	446.4
20	2.48	402.9
21	2.74	365.4
22	3.00	333.0
23.2	3.34	299.4
24	3.57	279.8
25	3.88	257.9
26	4.19	238.4
27	4.52	221.1
28	4.86	205.6
30	5.58	179.1
32	6.35	157.4
34	7.17	139.4
36	8.04	124.4
37	8.49	117.7
38	8.96	111.6
40	9.93	100.7
42	10.95	91.4
45	12.57	79.6
47	13.71	73.0
48	14.30	69.9
50	15.51	64.5
53	17.43	57.4
56	19.46	51.4
57.5	20.52	48.7
60	22.34	44.8
63	24.63	40.6
66	27.03	37.0
67.5	28.27	35.4
70	30.40	32.9
73.5	33.52	29.8
75	34.90	28.7
77.5	37.27	26.8
80	39.71	25.2
83	42.75	23.4
85	44.83	22.3
88	48.05	20.8
90	50.26	19.9
93	53.67	18.6
95	56.00	17.9
98	59.59	16.8
100	62.05	16.1
105	68.41	14.6
106	69.72	14.3
110	75.08	13.3
115	82.06	12.2
120	89.35	11.2
125	96.95	10.3

Density 7.90 g/cm³, diameter squared x 0.006205. Sizes are the published range at the nominal diameters shown.

Ordering Super duplex 2507 hot rolled round bar

An enquiry for this bar states the grade and the governing standard, ASTM A479 or EN 10088-3, the solution annealed condition, the diameter with the tolerance to ASTM A484 or EN 10060, the surface as black, spot ground or fully ground, the cut length, the quantity, the EN 10204 certificate type, and any further requirement such as NACE MR0175 and ISO 15156 acceptance, ultrasonic testing or PMI.