Sealmet HC-4, alloy 426, ASTM F31, UNS k94760, (Fe-42Ni-6Cr), Chinese 4J6
A controlled expansion alloy, consisting of 42% Nickel, 6% Chromium, balance Iron; used in a wide variety of electronic applications, especially for glass seals.
Forms: Sheet/Plate, Bar/Rod/Wire/Coil,Capillary/Pipe/Tube

Description

A nickel-chromium-iron which has been developed to match the thermal expansion characteristics of 0120 glass. An additional advantage of this alloy for glass-to-metals seals is the tight dark green oxide coating formed by wet hydrogen annealing at 1900/2200°F (1038/1204°C) for one hour. The oxide tends to flux with the glass and make it a vacuum tight seal if the surfaces are clean. To obtain the necessary surface cleanliness, pickle in muriatic acid.

Application

Glass to metal seals for a variety of electronic tubes and CRT tubes. It is supplied in wire form for compression seals.

parameter

Cross Reference:

Russia	USA	Japan	France	Germany
H42 X 6	42Ni-6Cr Carpenter426 Sylvania4 Sealmet4	NRS-1 YEF-426 SNC	ASV(426) Ni42Cr6	Vacovit426 (NiCr426

Typical chemistry:

C	P	S	Mn	Si	Al	Ni	Cr	Fe
≤
0.05	0.020	0.020	0.25	0.30	0.20	41.5-42.5	5.5-6.3	balance

Physical property:

Density :0.29  lb/in³,  8.2 g/cm3

Melting Range: 2600°F (1430°C)

Average Coefficient of Linear Expansion:

Heat Treatment of the Samples	Mean Coefficient of Linear Expansion
	20 to 300℃	20 to 400℃
To be heat treated at a temperature of 1130±20℃ the hydrogen, hold for 15 min., cool to 200℃ at a rate less than 5℃/min	7.6-8.3	9.5-10.2

Mean Coefficient of Thermal Expansion

20-100℃	20-200℃	20-300℃	20-400℃	20-500℃	20-600℃
6.8	7.0	7.7	9.7	11.1	12.2

The mechanical property of Alloy 42-6:

Tensile Strength	80KSI	552MPA
Yield Strength	40KSI	276MPA
Elongation	30%
Hardness	Rb 71

Size Range

Sheet	Thickness:0.10mm~3.50mm, width: ≤300mm
Plate	Thickness:3.5mm~40.0mm, width: ≤500mm
Round wire	Thickness:0.10mm~5.0mm
Flat Wire	Dia 0.5mm~Dia 5.0mm, length≤1000
Rod	Dia 5.0mm~Dia 8.0mm, length≤2000
	Dia 8.0mm~Dia 32.0mm, length≤2500
	Dia 32.0mm~Dia180.0mm, length≤1000
Capillary	OD 8.0mm~1.0mm,ID 0.1~8.0 length≤2500
Pipe	OD 120mm~8.0mm,ID 8.0~129 length≤4000

Condition: (With max tolerance) cold rolled, cold drawn, hot rolled , hot forging ,peeled turned ,bright ,bright annealed