Monel K-500 Introduction

Overview

As a leading supplier & manufacturer in China, AEETHER supply cost-effective Monel K-500 Products.

MONEL® alloy K-500 (UNS N05500 / W.Nr. 2.4375) is a nickel-copper alloy which combines the excellent corrosion resistance of MONEL alloy 400 with the added advantages of greater strength and hardness. The increased properties are obtained by adding aluminum and titanium to the nickel-copper base, and by heating under controlled conditions so that submicroscopic particles of Ni3 (Ti, Al) are precipitated throughout the matrix. The thermal processing used to effect precipitation is commonly called age hardening or aging.

Typical applications for MONEL alloy K-500 products are chains and cables, fasteners and springs for marine service; pump and valve components for chemical processing; doctor blades and scrapers for pulp processing in paper production; oil well drill collars and instruments, pump shafts and impellers, non-magnetic housings, safety lifts and valves for oil and gas production; and sensors and other electronic components.

A useful characteristic of the alloy is that it is virtually nonmagnetic, even at quite low temperatures. It is possible, however, to develop a magnetic layer on the surface of the material during processing. Aluminum and copper may be selectively oxidized during heating, leaving a magnetic nickel-rich film on the outside of the piece. The effect is particularly noticeable on thin wire or strip where there is a high ratio of surface to weight. The magnetic film can be removed by pickling or bright dipping in acid, and the nonmagnetic properties of the material will be restored.

The combination of low magnetic permeability, high strength and good corrosion resistance has been used to advantage in a number of applications, notably oil-well surveying equipment and electronic components.

MONEL alloy K-500 has been found to have exceptionally good dimensional stability, both in long-time exposure tests and in cyclic tests. This property of the alloy has led to its use in high-precision devices, such as gyros. Age hardening causes an initial volume contraction. An annealed rod contracted 2.5 x 10-4 in. per in. during aging.

Mechanical Properties

The low-temperature properties of MONEL alloy K-500 are outstanding. Tensile and yield strengths increase with decrease in temperature while ductility and toughness are virtually unimpaired. No ductile-to-brittle transformation occurs even at temperatures as low as that of liquid hydrogen. Thus the alloy is suitable for many cryogenic applications.

Properties of alloy K-500 base metal and welded sheet at temperatures down to -423°F. Welds can be produced with the strength of agehardened base metal with no serious loss in ductility if aging treatments are performed after welding annealed material. Welding of age-hardened material should be avoided because of greatly reduced ductility.

Corrosion Resistance

The corrosion resistance of MONEL alloy K-500 is substantially equivalent to that of alloy 400 except that, when in the age-hardened condition, alloy K-500 has a greater tendency toward stress-corrosion cracking in some environments.

MONEL alloy K-500 has been found to be resistant to a sour-gas environment. After 6 days of continuous immersion in saturated (3500 ppm) hydrogen sulfide solutions at acidic and basic pHs (ranging from 1.0 to 11.0), U-bend specimens of age-hardened sheet showed no cracking. Hardness of the specimens ranged from 28 to 40 Rc.

The combination of very low corrosion rates in highvelocity sea water and high strength make alloy K-500 particularly suitable for shafts of centrifugal pumps in marine service. In stagnant or slow-moving sea water, fouling may occur followed by pitting, but this pitting slows down after a fairly rapid initial attack.

Physical Properties

Density		g/cm3	8.44
		lb/in.3	0.305
Melting Range		°F	2400 - 2460
		°C	1315 - 1350
Modulus of Elasticity	Tension	103 ksi	26.0
	Torsion	103 ksi	9.5
Poisson’s Ratio		Aged material at room temperature	0.32

Mechanical Properties

Form and Condition	Tensile Strength		Yield Strength (0.2% Offset)		Elongation, %	Hardness
	ksi	MPa	ksi	MPa		Brinell (3000-kg)	Rockwell B
Rod and Bar
Hot-Finished	90-155	621-1069	40-110	276-758	45-20	140-315	75B-35C
Hot-Finished, Aged	140-190	965-1310	100-150	690-1034	30-20	265-346	27-38C
Hot-Finished, Annealed	90-110	621-758	40-60	276-414	45-25	140-185	75-90B
Hot-Finished, Annealed and Aged	130-165	896-1138	85-120	586-827	35-20	250-315	24-35C
Cold-Drawn, As-Drawn	100-140	690-965	70-125	483-862	35-13	175-260	88B-26C
Cold-Drawn, Aged	135-185	931-1276	95-160	655-1103	30-15	255-370	25-41C
Cold-Drawn, Annealed	90-110	621-758	40-60	276-414	50-25	140-185	75-90B
Cold-Drawn, Annealed and Aged	130-190	896-1310	85-120	586-827	30-20	250-315	24-35C
Sheet, Cold-Rolled
Annealed	90-105	621-724	40-65	276-448	45-25	-	85B max.
Strip, Cold-Rolled
Annealed	90-105	621-724	40-65	276-448	45-25	-	85B max.
Annealed and Aged	130-170	896-1172	90-120	621-827	25-15	-	24C min.
Spring Temper	145-165	1000-1138	130-160	896-1103	8-3	-	25C min.
Spring Temper, Aged	170-220	1172-1517	130-195	896-1345	10-5	-	34C min.
Tube and Pipe, Seamless
Cold-Drawn, Annealed	90-110	621-758	40-65	276-448	45-25	-	90B max.
Cold-Drawn, Annealed and Aged	130-180	896-1241	85-120	586-827	30-15	-	24-36C
Cold-Drawn, As-Drawn	110-160	758-1103	85-140	586-965	15-2	-	95B-32C
Cold-Drawn, As-Drawn, Aged	140-220	965-1517	100-200	690-1379	25-3	-	27-40C
Plate
Hot-Finished	90-135	621-931	40-110	276-758	45-20	140-260	75B-26C
Hot-Finished, Aged	140-180	965-1241	100-135	690-981	30-20	265-337	27-37C
Wire, Cold Drawn
Annealed	80-110	552-758	35-65	241-448	40-20	-	-
Annealed and Aged	120-150	827-1034	90-110	621-758	30-15	-	-
Spring Temper	145-190	1000-1310	130-180	896-1241	5-2	-	-
Spring Temper, Aged	160-200	1103-1379	140-190	965-1310	8-3	-	-