JIS G3462 Alloy Steel Tubes for Boiler and Heat Exchanger

Model: JIS G3462

Item specifics

Type: Hot Rolled / Cold Drawn

Delivery Condition: As Rolled, Cold Drawn, Normalizing Rolled

Review

Description

JIS G3462 Alloy Steel Tubes for Boiler and Heat Exchanger

the alloy steel tubes used for exchanging heat between the inside and outside of the tube, such as water tubes, smoke tubes, superheater tubes and air preheater tubes of boilers, and heat exchanger tubes, condenser tubes and catalyst tubes used in chemical and petroleum industries. It is not applicable to the steel tubes for heating furnace and steel heat exchanger tubes for low temperature service .

G3462 Alloy Steel Tubes Size

Outside diameter:10-200 mm

Wall thickness: 1-20mm

Length: 7meter or under/over

Hot finished OD tolerance: +0.4/-0.8mm

Cold finished OD tolerance: +/-0.1mm

Hot finished WT tolerance: +30/-0%

Cold finished WT tolerance: +20/-0%

G3462 Alloy Steel U-bend tubes

The U-bend tubes shall be made by cold-bending process, and the bending radius shall be at least 1.5 times the outside diameter of the tube.

The bent portion of the tube shall not be heat treated in general. When required by the purchaser, the heat treatment may be agreed between the purchaser and the manufacturer.

G3462 Alloy Steel Tubes manufacturing method

Designation of grade		Designation of manudacturing method
		Tube manufacturing method	Finishing method
Molybdenum steel tube	STBA12	Seamless : S Electric resistance welded : E	Hot finished : H Cold finished : C As electric resistance welded : G
	STBA13
Chromium-molybdenum steel tube	STBA20
	STBA22
	STBA23
	STBA24
	STBA25	Seamless : S	Hot finished : H Cold finished : C
	STBA26

G3462 Alloy Steel Tubes Chemical composition

Designation of grade	C	Si	Mn	P	S	Cr	Mo
STBA12	0.10 to 0.20	0.10 to 0.50	0.30 to 0.80	0.035 max.	0.035 max.	—	0.45 to 0.65
STBA13	0.15 to 0.25	0.10 to 0.50	0.30 to 0.80	0.035 max.	0.035 max.	—	0.45 to 0.65
STBA20	0.10 to 0.20	0.10 to 0.50	0.30 to 0.60	0.035 max.	0.035 max.	0.50 to 0.80	0.40 to 0.65
STBA22	0.15 max.	0.50 max.	0.30 to 0.60	0.035 max.	0.035 max.	0.80 to 1.25	0.45 to 0.65
STBA23	0.15 max.	0.50 to 1.00	0.30 to 0.60	0.030 max.	0.030 max.	1.00 to 1.50	0.45 to 0.65
STBA24	0.15 max.	0.50 max.	0.30 to 0.60	0.030 max.	0.030 max.	1.90 to 2.60	0.87 to 1.13
STBA25	0.15 max.	0.50 max.	0.30 to 0.60	0.030 max.	0.030 max.	4.00 to 6.00	0.45 to 0.65
STBA26	0.15 max.	0.25 to 1.00	0.30 to 0.60	0.030 max.	0.030 max.	8.00 to 10.00	0.90 to 1.10

G3462 Alloy Steel Tubes Heat treatment

Designation of grade	Heat treatment
STBA12 STBA13	Low temperature annealing, isothermal annealing, full annealing, normalizing or normalizing followed by tempering
STBA20 STBA22	Low temperature annealing, isothermal annealing, full annealing or normalizing followed by tempering
STBA23 STBA24 STBA25 STBA26	Isothermal annealing, full annealing or normaHzing followed by tempering
Notes a) Low temperature annealing shall not be applied to the electric resistance welded steel tube. b) The tempering temperature for STBA 23, STBA 24, STBA 25 and STBA 26 shall be 650 °C or higher.

G3462 Alloy Steel Tubes Appearance

The appearance of tubes shall be as follows.

a) The tube shall be practically straight, and the both ends shall be practically perpendicular to the tube axis.

b) The inside and outside surfaces of the tube shall be finished well without defects detrimental to use. In the case of electric resistance welded steel tube, the swelling of inside surface of the weld shall be 0.25 mm or under. The purchaser may specify the inside swelling to be 0.15 mm or less for tubes of 50.8 mm or under in outside diameter and 3.5 mm or under in wall thickness.

c) The surface of the tube may be repaired by grinding, machining or other methods, provided that the wall thickness after repairing still satisfies the specified tolerance on thickness.

d) The surface of repaired part shall be smooth along the contour of the tube.

G3462 Alloy Steel Tubes Tests

Chemical analysis

Mechanical test

Hydraulic test or nondestructive test

G3462 Alloy Steel Tubes Marking

Each tube which passed the inspection shall be marked with the following items. Tubes may be bundled together and marked for each bundle by a suitable means, when required by the manufacturer or when the small outside diameter of the tubes is an obstacle to marking on each tube. The arrangement of items is not specified.