NiMo16Cr16Ti Forgings

What NiMo16Cr16Ti is and when to specify it

NiMo16Cr16Ti carries roughly equal chromium and molybdenum at about 16% each. The molybdenum handles reducing acids such as sulphuric, hydrochloric and phosphoric. The chromium builds and repairs a passive oxide film, so the same part also holds up in oxidising conditions including wet chlorine, hypochlorite and aerated chloride streams. Process equipment rarely sees one clean chemistry, and this balance is the main reason the grade is specified.

The composition limits matter as much as the alloying additions. Carbon is capped at 0.015%, silicon at 0.08% and iron at 3.0%, and up to 0.70% titanium is added to combine with residual carbon. With little free carbon in the matrix, chromium and molybdenum stay dissolved rather than migrating to the grain boundaries as carbides during a long hold at intermediate temperature. This is what is meant by describing the grade as thermally stable.

The practical effect is that a thick NiMo16Cr16Ti forging can be welded into a heavy assembly without post-weld solution annealing, and can run at intermediate temperature without the heat-affected zone losing corrosion resistance. Alloy C-276 in the same duty needs more care with heat input and, on severe sections, may require a post-weld anneal. Where a part is heavy, welded or thermally cycled, that difference is the reason to accept the higher material cost.

Chemical composition of NiMo16Cr16Ti (UNS N06455)

The table below is the specification range Jiangyin Jiangnan Metal forges to. Every heat is supplied with a ladle analysis on the mill certificate; product analysis on the finished forging can be added on request. The three highlighted rows are the restrictions that give the alloy its thermal stability.

Limits per DIN 17744 (2.4610) and ASTM B574 (UNS N06455). Where a purchase order names a tighter internal specification, state it on the order and it will be certified.

Mechanical properties of NiMo16Cr16Ti forgings

Typical room-temperature values, solution annealed

These are representative results for solution-annealed and rapidly quenched NiMo16Cr16Ti forgings. They vary with section size and quench rate. A heavy section cools more slowly at the core and will normally test at the lower end.

Hardness values converted from Rockwell B. Typical values are for design screening only. The mill test certificate issued with each forging governs acceptance. Specified minima to ASTM B574 / B564 are tensile 690 MPa (100 ksi), yield 275 MPa (40 ksi) and elongation 40%; the maximum hardness normally accepted is 220 HB. Acceptance minima are those of the product standard in force or of your purchase specification, whichever is stricter; state them on the order and they will be certified.

Physical properties

Nominal values compiled from published alloy literature for guidance. Thermal conductivity is about a quarter that of carbon steel, which affects the quench on heavy sections where the core cools slowly. Quench severity is therefore specified on the order rather than left to the shop.

Corrosion resistance and service limits

NiMo16Cr16Ti is a general-purpose corrosion-resistant alloy rather than a specialist. For most individual acids a more resistant grade exists. Its value is coverage: one material handles both reducing and oxidising conditions, which suits process streams whose chemistry varies.

Behaviour depends on concentration, temperature, aeration and contaminants. A laboratory coupon test in the actual process fluid is the only reliable confirmation of a material selection. Intergranular corrosion testing to ASTM G28 Method A can be included in the order and reported on the certificate.

NiMo16Cr16Ti vs C-276 vs C-22: how to choose

All three are nickel-chromium-molybdenum alloys used in the same broad duties. They differ in chromium level, in whether tungsten is present, and in how well they survive welding and intermediate-temperature exposure.

NiMo16Cr16Ti equivalent designations

Trademark notice. Hastelloy® is a registered trademark of Haynes International, Inc.; Nicrofer® is a registered trademark of VDM Metals. Jiangyin Jiangnan Metal Co., Ltd. is not affiliated with, sponsored by or endorsed by either trademark holder. Those names appear here only to identify the equivalent material specification. Material we forge is correctly described as NiMo16Cr16Ti / W.Nr. 2.4610 / UNS N06455: the same generic chemistry, manufactured independently. Designations marked "nearest" are close but not identical; where a design registration or code case is involved, order to the UNS number and verify equivalence on the mill certificate.

Applicable standards by product form

Ultrasonic examination of forgings is covered by EN 10228-3. EN 1048 is a test method for concrete and does not apply to forgings. Where an older specification or quotation cites EN 1048-3, confirm the intended standard before the order is placed.

NiMo16Cr16Ti forgings we produce

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory. Every item below is forged to the customer's drawing or dimensional sketch. There is no fixed catalogue, no tooling charge and no minimum order quantity by piece.

Size and weight capability

Machining allowance is normally 6–20 mm per surface depending on section size, unless your drawing states otherwise. Finish-machined parts to print are also supplied. For nickel alloys the practical maximum is set by available ingot size rather than by press capacity, so confirm large sizes with the enquiry. Plant: 1 t, 3 t, 5 t and 9 t open-die hammers, a 5,000-tonne hydraulic press, and 3 m and 6 m seamless ring-rolling mills.

How we make NiMo16Cr16Ti forgings

1. Melting. NiMo16Cr16Ti stock is melted by EAF + VOD, with ESR remelting to improve cleanliness and reduce segregation. The low carbon and low silicon limits that give this grade its thermal stability are controlled here, not corrected later.
2. Heat verification. Heat chemistry is checked by optical emission spectrometer against the NiMo16Cr16Ti limits, with particular attention to carbon, silicon and titanium, before any material is heated.
3. Open-die forging. Hot worked from approximately 1,175 °C down to 950 °C with a controlled reduction ratio, to close porosity and develop a wrought grain flow that follows the part contour. Rings are ring-rolled seamless. The workpiece is reheated rather than finished below the minimum forging temperature, since this alloy work-hardens quickly.
4. Solution annealing. Held at approximately 1,065 °C (1,950 °F), then rapid water quenched. NiMo16Cr16Ti is not age hardened. The quench holds carbides in solution and keeps chromium and molybdenum available for corrosion resistance. Heavy sections are quenched aggressively because the alloy's low thermal conductivity slows the core.
5. Descaling and machining. Descaled and pickled, then rough or finish machined to your drawing with the agreed allowance. Rigid setups, positive rake, modest speeds and heavy positive feeds, with flood coolant.
6. Non-destructive testing. Ultrasonic examination to EN 10228-3, SEP 1921, ASTM A388 or your nominated class. Liquid penetrant, intergranular corrosion testing to ASTM G28 Method A, and dimensional inspection as required.
7. Certification and despatch. EN 10204 3.1 mill certificate as standard; 3.2 with third-party witness (TÜV, BV, LR, SGS, DNV) on request. Hard stamped, preserved and packed for sea or air freight.

Where NiMo16Cr16Ti forgings are used

Most of these applications share the same conditions: welded heavy-section equipment in chloride-bearing service. Where the part is thin and the process chemistry is stable, a lower-cost grade is usually adequate. Where the part is thick, welded into an assembly and cycled through intermediate temperature, such as a scrubber flange, a tube sheet or a reactor nozzle, NiMo16Cr16Ti avoids intergranular attack in the heat-affected zone. Service limits are set out in the corrosion section.

Testing, inspection and certification

• Chemical analysis. Spectrometric heat analysis and, on request, product analysis on the finished forging.
• Mechanical testing. Room-temperature tensile, yield, elongation and hardness; elevated-temperature tensile and impact testing to your specification.
• Ultrasonic testing. EN 10228-3, SEP 1921 Class C/D/E, ASTM A388 or a nominated customer class.
• Surface NDT. Liquid penetrant examination per ASTM E165 / ASME V Article 6.
• Corrosion testing. Intergranular corrosion testing to ASTM G28 Method A, recommended on this grade since resistance to intergranular attack is the reason it is specified.
• Positive material identification. PMI on the finished forging on request. Recommended on Ni-Cr-Mo work, where C-4 and C-276 are easily confused.
• Heat treatment record. Furnace chart and quench record for the solution anneal, issued with the certificate.
• Certification. EN 10204 3.1 as standard; EN 10204 3.2 witnessed by TÜV, BV, LR, SGS or DNV on request. Full heat traceability and hard stamping with grade and heat number.

Inspection plant includes a universal testing machine, impact testing machine, hardness testers, magnetic particle and ultrasonic flaw detection, spectrometer and metallographic microscope. Jiangyin Jiangnan Metal operates an ISO 9001:2015 quality system.

Request a quotation for NiMo16Cr16Ti forgings

Related nickel alloy grades we forge