Annealed Alloy 825 Round Bar , Incoloy 825 Bar Peeled Surface Anti Corrosion

Product Specification

nickel alloy Incoloy 825 round bar

INCOLOY® alloy 825 (UNS N08825/W.Nr. 2.4858) is a nickel-iron-chromium alloy with additions of molybdenum, copper, and titanium. The alloy’s chemical composition, given in Chemical composition, is designed to provide exceptional resistance to many corrosive environments. The nickel content is sufficient for resistance to chloride-ion stress-corrosion cracking. The nickel, in conjunction with the molybdenum and copper, also gives outstanding resistance to reducing environments such as those containing sulfuric and phosphoric acids. The molybdenum also aids resistance to pitting and crevice corrosion. The alloy’s chromium content confers resistance to a variety of oxidizing substances such as nitric acid, nitrates and oxidizing salt. The titanium addition serves, with an appropriate heat treatment, to stabilize the alloy against sensitization to intergranular corrosion.

The resistance of INCOLOY alloy 825 to general and localized corrosion under diverse conditions gives the alloy broad usefulness. Applications include chemical processing, pollution control, oil and gas recovery, acid production, pickling operations, nuclear fuel reprocessing, and handling of radioactive wastes. Applications for alloy 825 are similar to those for INCOLOY alloy 020.

Physical constants

Density, lb/in3.....................................................................0.294

Mg/m3 ....................................................................8.14

Melting Range, °F .....................................................2500-2550

°C .....................................................1370-1400

Specific Heat, Btu/lb•°F ....................................................0.105

J/kg•°C .........................................................440

Curie Temperature, °F .......................................................<-320

°C ......................................................<-196

Permeability at 200 oersted (15.9 kA/m)...........................1.005

Chemical composition, %

Nickel ..........................................................................38.0-46.0

Iron...............................................................................22.0 min.

Chromium....................................................................19.5-23.5

Molybdenum ...................................................................2.5-3.5

Copper ............................................................................1.5-3.0

Titanium...........................................................................0.6-1.2

Carbon........................................................................0.05 max.

Manganese ...................................................................1.0 max.

Sulfur ..........................................................................0.03 max.

Silicon ...........................................................................0.5 max.

Aluminum......................................................................0.2 max.

Mechanical Properties

INCOLOY alloy 825 has good mechanical properties from cryogenic temperatures to moderately high temperatures. Exposure to temperatures above about 1000°F (540°C) can result in microstructural changes (phase formation) that significantly lower ductility and impact strength. For that reason, the alloy is not normally used at temperatures where creep-rupture properties are design factors.

In high-temperature tensile properties, the tests were conducted on cold-drawn rod of 0.75-in. (19- mm) diameter annealed at 1725°F (940°C)/1 hr.

Compressive yield strength of the alloy is similar to tensile yield strength. Tests on annealed rod of 1.0-in. (25-mm) diameter produced a compressive yield strength (0.2% offset) of 61,400 psi (423 MPa) compared with a tensile yield strength of 57,500 psi (396 MPa). Ultimate tensile strength of the material was 104,500 psi (720 MPa).

INCOLOY alloy 825 has good impact strength at room temperature and retains its strength at cryogenic temperatures.

Corrosion Resistance

The outstanding attribute of INCOLOY alloy 825 is its high level of corrosion resistance. In both reducing and oxidize environments, the alloy resists general corrosion, pitting, crevice corrosion, intergranular corrosion, and stress-corrosion cracking. Some environments in which INCOLOY alloy 825 is particularly useful are sulfuric acid, phosphoric acid, sulfur containing flue gases, sour gas and oil wells, and sea water.

Fabrication

INCOLOY alloy 825 products are heat treated during manufacturing at the mill to develop the optimum combination of stabilization, corrosion resistance, mechanical properties, and formability. To maintain these properties during fabrication, subsequent anneals should be performed between 1700 to 1800°F (930 to 980°C) followed by rapid air cooling or water quenching. Heat treatment in the lower end of the range is acceptable for stabilization. However, annealing at temperatures in the higher end of this range may be preferred for softness and grain structure for forming and deep-drawing while maintaining corrosion resistance. Quenching is usually not necessary for parts of thin cross section (e.g., sheet, strip and wire), but may be desired to avoid sensitization in products of heavier cross section.

Hot and Cold Forming

The hot-working range for INCOLOY alloy 825 is 1600 to 2150°F (870 to 1180°C). For optimum corrosion resistance, final hot working should be done at temperatures between 1600 and 1800°F (870 and 980°C).

Cooling after hot working should be air cool or faster. Heavy sections may become sensitized during cooling from the hot-working temperature, and therefore be subject to intergranular corrosion in certain media. A stabilizing anneal restores resistance to corrosion. If material is to be welded or subjected to further thermal treatment and subsequently exposed to an environment that may cause intergranular corrosion, the stabilizing anneal should be performed regardless of cooling rate from the hot-working temperature.

Cold-forming properties and practices are essentially the same for INCOLOY alloy 825 as for INCONEL alloy 600. Although work-hardening rate is somewhat less than for the common grades of austenitic stainless steels, it is still relatively high. Forming equipment should be well powered and strongly built to compensate for the increase in yield strength with plastic deformation.

Machining

All standard machining operations are readily performed on INCOLOY alloy 825. The alloy normally has optimum machining characteristics in the annealed temper.

Available Products and Specifications

INCOLOY Alloy 825 is designated as UNS N08825 and Werkstoff Number 2.4858. It is listed in NACE MR0175 for oil and gas service. Alloy 825 is available as pipe, tube, round bar, flat bar, forging.

Rod, Bar, and Forging - BS 3076NA16, ASTM B 425, ASTM B 564, ASME SB 425, ASME SB 564, ASME Code Case N-572, DIN 17752, DIN 17753, DIN 17754, VdTÜV 432, ISO 9723, ISO 9724, ISO 9725

Pipe and Tube - BS 3074NA16, ASTM B 163, ASTM B 423, ASTM B 704, ASTM B 705, ASTM B 751, ASTM B 775, ASTM B 829, ASME SB 163, ASME SB 423, ASME SB 704, ASME SB 705, ASME SB 751, ASME SB 775, ASME SB 829, ASME Code Case 1936, DIN 17751, VdTÜV 432, ISO 6207

Product size range
Diameter: 100mm - 600mm
Length: on request
 
Production Process