UNS N07090 / W.Nr. 2.4632 Nickel Based Alloys Good Formability And Weldability

Nickel based Alloy 90 (UNS N07090, W.Nr. 2.4632) semi-products for clean energy and power generating

1 PRODUCT

Nickel based Alloy 90 (UNS N07090, W.Nr. 2.4632) semi-products for clean energy and power generating.

Standard semi-product forms include sheet, strip, plate, round bar, flat bar, forging, hexagon, ring, disc, wire and fastener etc.

2 EQUIVALENT DESIGNATION

GH4090, UNS N07090, NIMONIC® alloy 90, W.Nr. 2.4632, 2.4969, AWS 030

3 APPLICATION

The alloy is used for turbine blades, discs, forgings, ring sections, fasteners, clamp, seal ring, elastic element and hot-working tools.

4 OVERVIEW

Alloy 90 is a wrought nickel-chromium-cobalt base alloy strengthened by additions of titanium and aluminum. It has been developed as an age-hardenable creep- resisting alloy for service at temperatures up to 920°C (1688°F).

The alloy has high tensile strength and creep resistance, good oxidation resistance and corrosion resistance in 815~870°C, high fatigue strength and good formability and weldability under the action of repeated cooling and heating.

5 CHEMICAL COMPOSITION (wt%):

Table 1 (wt%)

6 PHYSICAL PROPERTIES

Density:ρ=8.18 g/cm³(0.296lb/in³)

Melting range:1310-1370℃(2390-2500°F)

7 MECHANICAL PROPERTIES

Tensile Properties of Extruded Bar Subsequently Forged

Heat treatment 8 h / 1080°C (1975°F) / AC + 16 h / 700°C (1290°F) / AC

8 CORROSION RESISTANCE

Oxidation in Air (continuous heating)

Descaled weight loss (mg/cm²) after 100 hours at

Intermittent Heating (cooling to room temperature every 24 hours)

Descaled weight loss (mg/cm²) after 100 hours at

Resistance to atmospheres containing SO₂

9 MICROSTRUCTURE

The main enhancement of the alloy is the γ′-Ni₃(Al,Ti), which precipitates into different square particles in the grain, which is also visible in the grain boundary. The carbide is precipitated in a discontinuous strand in the grain boundary.

10 WORKING INSTRUCTION

Formability

The alloy is easily to get internal crack when forging, not allowed heavy hammer strikes, no low temperature chamfering.

Before charging into the heating furnace, the furnace temperature cannot be higher than 700°C. The final heating temperature is 1150±10°C. Forging start at temperature not less than 1060°C, and the final forging temperature is not less than 950°C.

The rolling heating temperature is 1160°C, and the finishing temperature not lower than 950°C.

Cold drawn product shall undergo cold deformation of 8%~12% after final intermediate annealing.

Hot working

Alloy 90 should be hot worked in the range 1050-1200°C (1922-2192°F).

Interstage annealing

Interstage annealing should be at 1040°C (1904°F) followed by a water quench or air cooling.

Cold drawn bar

1080±10°C; holding time see table below, air cooling or water cooling, +750±10°C,4h, air cooling.

Sheet and strip (soft state)

Softened at 1100~1150°C,1~10min, cooled in appropriate medium, +750±10°C, 4h, air cooled

Sheet and strip (hard state)

700~725°C,4h, air cooled

Spring wire (cold drawn)

600±10°C,16h, air cooled or 650±10°C,4h, air cooled

Spring wire (cold drawing and solid solution)

1080±10°C, 8h, air cooling +700~750, 4h, air cooling

Machining

Alloy 90 should be in the fully heat-treated condition for all machining operations. The high material hardness in this condition, 250-350 HV, requires the use of stringent machining techniques.

11 STANDARD SPECIFICATION

Rod, Bar, Wire and Forging Stock

BS HR2, HR501, HR502 and HR503

BS 3075 NA 19

SAE AMS 5829 Nickel Alloy, Corrosion and Heat Resistant, Welding Wire 56ni 19.5cr 16.5co 2.5ti 1.5al Vacuum Induction Melted

AECMA PrEN 2295, 2296, 2297, 2400, 2401, 2669 and 2670.

ISO 15156-3 (NACE MR 0175)

NCK 20TA

Plate, Sheet and Strip

BS HR202

AECMA PrEN 2298.

Pipe and Tube

BS HR402

AECMA PrEn 2299

12 COMPETITIVE ADVANTAGE:

(1) More than 50 years experience of research and develop in high temperature alloy, corrosion resistance alloy, precision alloy, refractory alloy, rare metal and precious metal material and products.
(2) 6 state key laboratories and calibration center.
(3) Patented technologies.

(4) Ultra-purity smelting process: VIM + IG-ESR + VAR

(5) Excellent high performance.

13 BUSINESS TERM