EN 10028-4 X7Ni9 steel plate

EN 10028-4 X7Ni9 steel plate, also written as X7Ni9 (1.5663), DIN EN 10028-4 X7Ni9 and BS EN 10028-4 X7Ni9, is a 9% Ni (tight P, low V) nickel alloy flat product for pressure purposes with specified low-temperature properties. Gangsteel (HENAN GANG IRON AND STEEL) produces and exports X7Ni9 plates cut to size with Charpy V-notch tests at the ordered temperature, ultrasonic testing and EN 10204 3.1/3.2 certificates.

Data source: EN 10028-4:2017 (supersedes EN 10028-4:2009), Tables 1–4, with general requirements in EN 10028-1:2017. The current edition covers seven steel grades: 11MnNi5-3, 13MnNi6-3, 15NiMn6, 12Ni14, X12Ni5, X8Ni9, X7Ni9. The 2017 revision extended X8Ni9+QT640, X8Ni9+QT680 and X7Ni9 to 125 mm and added a clause on magnetization during handling. Always check the edition named on the purchase order.

EN 10028-4 X7Ni9 Chemical Composition (Cast Analysis, %)

C maxSi maxMnP maxS maxAl totalMo maxNb maxNiV max
0.100.350.30–0.800.0150.005–0.10–8.5–10.00.01

Cr + Cu + Mo ≤ 0.50%. Elements not listed shall not be intentionally added without the purchaser's agreement. Product analysis tolerances follow Table 2, for example C +0.02%, P +0.003/+0.005%, S +0.003% and Ni ±0.05/0.07/0.10% depending on the nickel level.

EN 10028-4 X7Ni9 Mechanical Properties at Room Temperature

Condition / thickness t (mm)Yield strength ReH min (MPa)Tensile strength Rm (MPa)Elongation A min (%)
t ≤ 30585680–82018
30 < t ≤ 50575680–82018

The table shows the values verified for t ≤ 50 mm. For the thickness range above 50 mm added in the 2017 edition (up to 125 mm), Gangsteel applies the yield values of EN 10028-4:2017 Table 3 and states them on the order confirmation.

EN 10028-4 X7Ni9 Minimum Impact Energy KV (J)

ConditionDirection+20°C0°C-20°C-40°C-50°C-60°C-80°C-100°C-120°C-150°C-170°C-196°C
+QTLongitudinal120120120120120120120120120120110100
+QTTransverse1001001001001001001001001001009080

* A minimum impact energy of 40 J may be agreed at enquiry and order. Mid-thickness test pieces and longitudinal verification can be agreed under Clauses 10 and 11.

Heat Treatment and Delivery Condition

Usual delivery condition: +QT (+N plus +NT also allowed for t < 15 mm). +N = normalized, +NT = normalized and tempered, +QT = quenched and tempered. Heat treatment temperatures and cooling conditions are given for guidance in Annex A (Table A.1) of EN 10028-4. Gangsteel records the actual heat treatment on the mill certificate.

Thickness, Size and Inspection

Standard thickness coverage for X7Ni9: up to 125 (2017 edition; 50 mm in 2009) mm. Gangsteel supplies widths 1500–4000 mm and lengths up to 12 m, plates cut to drawing, UT to EN 10160 (S1/E1 to S3/E4), residual magnetism checks and third-party inspection (TUV, BV, SGS, Lloyd's). PED 2014/68/EU projects receive EN 10204 3.1 or 3.2 documents.

Applications of EN 10028-4 X7Ni9

Large LNG storage tanks where owners demand the highest Charpy energy at -196°C, LNG import terminals, FSRU / FLNG cargo containment and other critical cryogenic pressure equipment.

Equivalent / Related Grades of EN 10028-4 X7Ni9

StandardComparable grade (approximate)
EN 10028-4X7Ni9 / 1.5663
Former national gradesno 1:1 DIN 17280 predecessor; developed as the highest-toughness 9% Ni grade of the series
InternationalASTM A553 Type I (QT 9% Ni), GB/T 3531 06Ni9DR, JIS G3127 SL9N590; X7Ni9 carries the strictest impact values of EN 10028-4
Other EN 10028-4 grades11MnNi5-3 | 13MnNi6-3 | 15NiMn6 | 12Ni14 | X12Ni5 | X8Ni9

Equivalents are engineering references only; chemistry, heat treatment and impact temperatures differ, so dual certification requires the stricter combined limits on the PO and MTC.

FAQ about EN 10028-4 X7Ni9 Steel Plate

What is EN 10028-4 X7Ni9 steel plate?

EN 10028-4 X7Ni9 (steel number 1.5663) is a 9% Ni (tight P, low V) nickel alloy steel plate for pressure equipment with specified low-temperature impact properties. It is ordered to EN 10028-4:2017 together with the general requirements of EN 10028-1:2017, and the full tables are on the EN 10028-4 X7Ni9 page.

What is the chemical composition of X7Ni9 to EN 10028-4?

The cast analysis of X7Ni9 is C 0.10% max, Si 0.35% max, Mn 0.30–0.80%, P 0.015% max, S 0.005% max, Ni 8.5–10.0%, Mo 0.10% max, Nb –% max and V 0.01% max, and Cr + Cu + Mo must not exceed 0.50%.

What are the yield strength and tensile strength of X7Ni9?

At room temperature X7Ni9 must reach t ≤ 30: ReH 585 MPa min; 30 < t ≤ 50: ReH 575 MPa min, a tensile strength Rm of 680–820 MPa and an elongation A of at least 18%.

What is the lowest impact test temperature for X7Ni9?

The lowest temperature with a specified minimum Charpy V-notch energy for X7Ni9 in EN 10028-4 Table 4 is -196°C, and the purchaser can choose any tabulated temperature down to that limit on the order.

What delivery condition is used for X7Ni9 plate?

The usual delivery condition for X7Ni9 is +QT (+N plus +NT also allowed for t < 15 mm), and the actual condition must be stated in the inspection document. Untreated delivery can be agreed, in which case tests are made on heat-treated test pieces.

What is the maximum thickness of EN 10028-4 X7Ni9?

EN 10028-4 specifies properties for X7Ni9 up to 125 (2017 edition; 50 mm in 2009) mm. Gangsteel confirms thicker or special sizes against the contracted edition at enquiry.

What are the equivalent grades of X7Ni9?

The closest comparable grades are ASTM A553 Type I (QT 9% Ni), GB/T 3531 06Ni9DR, JIS G3127 SL9N590; X7Ni9 carries the strictest impact values of EN 10028-4. Former national designations replaced by X7Ni9 include no 1:1 DIN 17280 predecessor; developed as the highest-toughness 9% Ni grade of the series. Equivalents are for engineering comparison only and do not replace the specified standard on the order.

Can a minimum impact energy of 40 J be specified?

Yes, for 11MnNi5-3, 13MnNi6-3, 15NiMn6, 12Ni14 and X12Ni5 a minimum of 40 J may be agreed at temperatures where the table shows lower transverse values. The 9% nickel grades X8Ni9 and X7Ni9 already have higher tabulated values.

Why must X7Ni9 plate be protected against magnetization?

Nickel alloy steels magnetize easily, and residual magnetism causes arc blow during welding. The 2017 edition added a clause on handling in relation to magnetization, so Gangsteel lifts these plates with clamps or vacuum lifters rather than magnets and can measure residual magnetism before shipment.

What inspection and certificates does Gangsteel supply with X7Ni9 plate?

Gangsteel supplies EN 10028-4 X7Ni9 plate with an EN 10204 3.1 certificate as standard, 3.2 certificates with third-party inspection on request, Charpy tests at the ordered temperature, and ultrasonic testing to EN 10160 or another agreed standard.

Related EN 10028-4 / Low Temperature Pressure Vessel Grades

EN 10028-4 Hub | EN 10028-4 11MnNi5-3 | EN 10028-4 13MnNi6-3 | EN 10028-4 15NiMn6 | EN 10028-4 12Ni14 | EN 10028-4 X12Ni5 | EN 10028-4 X8Ni9 | EN 10028-4 X7Ni9 | ASTM A553 | ASTM A353 / SA353 | GB/T 3531 | ASTM A533 | ASTM A537 | Pressure Vessel Steel Plate

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