Alloy 27,ASTM F-256,UNS K92801,(Fe-28Cr),Chinese 4J28
Alloy 27, it’s glass-to-metal sealing and iron-chromium alloy. Nominally 28 % chromium, in strip, bar, wire, and rod forms intended primarily for sealing to glass in electronic applications. UNS K92801 should only be considered for use at service temperatures below 300°C.
Forms: Sheet/Plate, Bar/Rod/Wire/Coil,Capillary/Pipe/Tube

Description

Alloy 27, it’s glass-to-metal sealing and iron-chromium alloy. Nominally 28 % chromium, in strip, bar, wire, and rod forms intended primarily for sealing to glass in electronic applications. UNS K92801 should only be considered for use at service temperatures below 300°C. The alloy is prone to sigma phase formation at temperatures close to 620°C, and exhibits brittle mechanical behavior after prolonged exposures at temperatures close to 475°C.

Application

It is applied to seal the equipment of the electric component with the soft glass.

parameter

Typical chemistry:

C	P	S	Mn	Si	Ni	N	Cr	Fe
≤
0.12	0.02	0.02	1.00	0.70	0.50	0.20	27.0-29.0	Balance

Notes: Under condition that the average coefficient of the linear expansion meets the requirements of the standard, the content of chromium is allowed to deviate from the stated range.

Heat Treatment of the Samples	Average Coefficient of Linear Expansion
	20～530°C
Heat to 1100±20°C, hold for 15min., cool to room tempreture in the air.	10.8～11.4

Notes: The hardness of the annealed strip should be no more than 170. Hardness inspection is not required when the thickness of the strip is less than 0.2mm.

Average Coefficient of Linear Expansion:

20-200℃	20-300℃	20-400℃	20-500℃	20-600℃	20-700℃	20-800℃
10.00	10.50	10.80	11.10	11.20	11.60	11.60

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