Ni 32.5 Cr 21 Mn 1.5 C 0.10 Si 1.0 Fe 39.5 Cu 0.75 S 0.015 Al 0.60 max. Ti 0.60 max

 

High Performance Alloys stocks and produces this grade in the following forms: Bar, sheet, plate, fasteners and forgings. Request quote on this grade.

 

Overview

UNS N08810 / UNS N08811
800HT is an iron-nickel-chromium alloy having the same basic composition as Alloy 800, with significantly higher creep rupture strength. The higher strength results from close control of carbon, aluminum and titanium contents in conjunction with a high temp anneal. The 800H modification was to control carbon (0.05 to 0.10%) and grain size to (>ASTM 5) to optimize stress rupture properties. 800HT has further modifications to the combined titanium and aluminum levels (0.85 to 1.2%) to ensure optimum high temperature properties. The alloy is dual certified and combines the properties of both forms.

The chemical balance allows the alloy to exhibit excellent resistance to carburization, oxidation and nitriding atmospheres. 800HT will not become embrittled even after long periods of usage in the 1200-1600 deg F range where many stainless steels become brittle. Excellent cold forming characteristics typically associated with the nickel-chromium alloys are exhibited with 800HT. When cold formed extensively the grain size produces a visibly undulated surface called "orange peel". 800HT can be welded by the common techniques used on stainless steels.

Typical applications for the alloy include ethylene pyrolysis, hydrocarbon cracking, cracking furnaces for vinyl chloride, diphenol and acetic acid. The alloy is also used for valves, fittings and other components exposed to corrosive attack from 1100 to 1800 deg F.

Round bar ranging from 3/4" to 6" diameter, and light gauge sheet and plate. Material can be supplied in random lengths, cut to order or machined to customer requirements. Machining includes drilling, threading, milling, CNC shapes, turning, tapping, flanges and others.

Chemistry

Chemical Requirements
	Ni	Cr	Mn	C	Si	Fe	C
Max	35.0	23.0	1.5	0.10	1.0		0.75
Min	30.0	19.0				39.5

Tensile Data

Mechanical Property Requirements
	Ultimate Tensile, min.	Yield Strength (0.2% OS)	Elong. in 2 in. or 50mm (or 4D) min., %	R/A	Hardness
Min	80 KSi	35 KSi	25
Max
Min	550 MPa	240 MPa
Max

 

Mechanical Property Requirements
	Ultimate Tensile, min.	Yield Strength (0.2% OS)	Elong. in 2 in. or 50mm (or 4D), min.,%	R/A	Hardness
Cold Worked/Annealed
Min	75 KSI	30 KSi	30
Max
Min	515 MPa	205 Mpa
Max
Hot Worked/Annealed
Min	75 KSi	30 KSi	30
Max
Min	515 Mpa	205 MPa
Max

Specifications

Form	Standard
Metal Type	UNS N08800 / N08810 / N08811
Bar	ASTM B408
Wire
Sheet	ASTM B409
Plate	ASTM B409
Fitting	ASTM B366
Forging	ASTM B564
Weld Wire
Weld Electrode

Machining

MACHINING DATA
Carbide tools are suggested for rates better than 50% of Type 304.
Machining Type	Suggested starting rates are:
Single Point turning :	Roughing - 0.15" depth, 0.015"/rev feed -175 SFM Finishing - 0.025" depth, 0.007"/rev feed - 200 SFM
Drilling :	1/4" Dia hole - 0.004"/rev feed - 60 SFM 1/2" Dia hole - 0.007"/rev feed - 60 SFM 3/4" Dia hole - 0.010"/rev feed - 60 SFM
Reaming :	Feed - same as drilling - 100 SFM
Side and Slot Milling :	Roughing - 0.25" depth - 0.007"/tooth feed - 125SFM Finishing - 0.050" depth - 0.009"/tooth feed - 140SFM
These rates are for carbide tools, Type C-2 for roughing, drilling and reaming. Type C-3 for finishing.

 

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