Inconel 690 Introduction

Overview

As a leading supplier & manufacturer in China, AEETHER supply cost-effective Inconel 690 Products.

INCONEL® alloy 690 (UNS N06690 / W. Nr. 2.4642) is a high-chromium nickel alloy having excellent resistance to many corrosive aqueous media and hightemperature atmospheres. In addition to its corrosion resistance, alloy 690 has high strength, good metallurgical stability, and favorable fabrication characteristics.

The substantial chromium content gives the alloy outstanding resistance to oxidizing chemicals and to high-temperature oxidizing gases. The high level of nickel imparts resistance to stresscorrosion cracking in chloride-containing environments as well as to sodium hydroxide solutions.

The properties of INCONEL alloy 690 are useful for various applications involving nitric or nitric/hydrofluoric acid solutions. Examples are tail-gas reheaters used in nitric acid production and heating coils and tanks for nitric/hydrofluoric solutions used in pickling of stainless steels and reprocessing of nuclear fuels.

The alloy’s resistance to sulfur-containing gases makes it an attractive material for such applications as coal-gasification units, burners and ducts for processing sulfuric acid, furnaces for petrochemical processing, recuperators, incinerators, and glass vitrification equipment for radioactive waste disposal.

In various types of high-temperature water, alloy 690 displays low corrosion rates and excellent resistance to stress-corrosion cracking. Thus, alloy 690 is widely used for steam generator tubes, baffles, tubesheets, and hardware in nuclear power generation.

Mechanical Properties

INCONEL alloy 690 has high strength over a broad range of temperatures. Mechanical properties of the alloy vary with product form and temper. Alloy 690 is normally used in the annealed temper, and strength characteristics described below are representative of annealed material. The usual annealing temperature is approximately 1900°F (1040°C).

Corrosion Resistance

INCONEL alloy 690 has excellent resistance to corrosion in a broad range of aqueous and high temperature environments. Because of its high chromium content, the alloy is particularly resistant to oxidizing conditions. Alloy 690 also offers excellent resistance to attack by sulfur at high temperatures.

Physical Properties

Density		g/cm3	8.19
		lb/in.3	0.296
Melting Range		°F	2450 - 2510
		°C	1343 - 1377
Specific Heat		Btu/lb-°F	0.107
		J/kg-°C	450
Electrical Resistivity		ohm-circ mil/ft	691
		μΩ-m	1.148
Permeability at 200 oersted		15.9 kA/m	1.001
Young’s Modulus		103 ksi	30.6
		GPa	211
Poisson’s Ratio			0.289

Mechanical Properties

Exposure Temperature		Exposure Time, h	Yield Strength (0.2% Offset)		Tensile Strength		Elongation %	Impact Strength
°F	°C		ksi	MPa	ksi	MPa		ft-lb	J
No exposure		-	41.0	283	103.5	714	48	140	190
1050	565	1000	48.5	334	105.5	727	45	115	156
		4000	47	324	105	724	45	126	171
		12000	45.5	314	105.5	727	44	121	164
1100	595	1000	62.5	431	107	738	45	144	195
		4000	46.5	321	106	731	43	125	170
		13428	45.5	314	105.5	727	44	125	170
1200	650	1000	46.8	323	105.5	727	46	146	198
		4000	48.5	334	106	731	54	132	179
		12000	46.1	318	108.5	748	41	127	172
1400	760	1000	50	345	107	738	44	158	214
		4000	44.4	306	103.5	714	44	148	201
		12000	46.5	321	103.5	714	46	136	184

Related Article