JIS G3462

JIS G3462 is a Japanese Industrial Standard that covers the specifications for alloy steel tubes used for exchanging heat on the inside and outside of the tube in high-temperature applications such as boilers, heat exchangers, and fired heaters. The standard specifies several grades of alloy steel tubes, including STBA12, STBA13, STBA20, and STBA22. The U-bend tubes made from cold-bending process also comply with the standard, with specific requirements for bending radius and heat treatment. JIS G3462 is an important standard for the manufacture and use of alloy steel tubes in high-temperature applications, especially in industries that require reliable and efficient heat transfer.

Scope

This Standard specifies the alloy steel tubes (hereafter referred to as "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.

This Standard applies to tubes with an outside diameter of 15.9 mm. to 139.8 mm.
With the preyious agreement of the  manufacturer, the purchaser may designate the  special quality requirements and designate U-bend tubes to be applied,given in Annex JA and Annex JBA respectively in addition to the requirements specified .in the. text of this Standard.

NOTE: The International Standards corresponding to this Standard and the symbol of degree of correspondence are as follows:
ISO 9329-2 : 1997 Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 2 : Unalloyed and alloyed steels with specified eleva ted tempera ture properties ISO 9330-2 : 1997 Welded steel tubes for pressure purposes - Technical delivery conditions - Part 2 : Electric resistance and induction welded unalloyed and alloyed steel tubes with specified elevated temperature properties (overall evaluation: MOD)The symbols which denote the degree of correspondence in the contents between the relevant International Standards and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/lEe Guide 21-1.

Normative references

The following standards contain provisions which, through reference in this text,constitute provisions of this Standard. The most recent editions of the standards (including amendments) indicated below shall be applied.

• JIS G 0320 Standard test method for heat analysis of steel products
• JIS G 0321 Product analysis and its tolerance for wrought steel
• JIS G 0404 Steel and steel products - General technical delivery requirements
• JIS G 0415 Steel and steel products - Inspection documents
• JIS G 0416 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
• JIS G 0567 Method of elevated temperature tensile test for steels and heat-resisting alloys
• JIS G 0582 Automated ultrasonic examination of steel pipes and tubes
• JIS G 0583 Automated eddy current examination of steel pipes and tubes
• JIS Z 2241 Metallic materials - Tensile testing - Method of test at room temperature
• JIS Z 2245 Rockwell hardness test - Test method
• JIS Z 8401 Guide to the rounding of numbers

Classification and symbols

Tubes shall be classified into grades, and the designation of grade and designation of manufacturing method shall be as given in table 1

Table 1 Designation of grade, designation of manufacturing method and marking

Manufacturing method

The manufacturing method shall be as follows.

(a)Tubes shall be manufactured by a combination of the manufacturing method and finishing method given in table 1
(b)The tubes of STBA 12, STBA 13, STBA 20 and STBA 22 shall be manufactured by seamless process or by electric resistance welding process and the tubes of STBA 23, STBA24, STBA 25 and STBA 26 shall be manufactured by seamless process.
(c)Tubes shall be subjected to the Heat treatment specified in table 22.Other heat treatments not specified in table 2 shall be agreed between the purchaser and the manufacturer.
(d) Plain end finishing shall be applied to the shape of tube end unless otherwise specified.

Table 2 Heat treatment

JIS G3462 specifies the alloy boiler steel tubes used for exchanging heat on the inside and outside of the tube, with 8 steel grades from STBA12-STBA26, it has the similar application as JIS G3461, steel tube of this specification could be supplied as U tube. However, it is not applicable to the steel tubes for heating furnace and those for heat exchangers of low temperature service. For final product, heat treatment of the bent portion is not usually performed. However, if there is a request from the orderer, agreement on heat treatment. Sunny Steel is an experienced boiler and pressure steel tube supplier which can offer you JIS G3462 steel tube of all grade and dimension range.

Chemical Compositions(%) of JIS G3462

Note:

OD refers to the outside diameter.

The above table is only applicable for heat exchanger alloy steel pipes. The buyer can appoint the upper limit value of tensile strength. The upper limit value of tensile strength is the above shown value plus 147 N/mm2.

For the alloy steel tube with the thickness of less than 8 mm, we use NO.12 sample for tensile test. The minimum elongation will be reduced by 1.5% from the table value when the thickness reduces 1 mm. The value ​​obtained will be rounded to an integer value according to JIS Z 8401 (a rounding method). When we take the electric resistance welded steel pipes for tensile test, we also choose NO.12 sample from the parts not containing welding seams.

Mechanical proertiesof JIS G3462

Packing: Bare/bundles/crates/crate protection at the both sides of tubes or as per customers’ requirements.
Painting: as requested.

The tubes shall be manufactured by seamless process, electric resistance welding process, or butt welding process, and those of other grades shall be manufactured by seamless process or electric resistance welding process. The tube shall be as manufactured or as cold-finished condition, or they shall be subjected to appropriate heat treatment.

The tubes shall be practically straight. and the two ends shall be at right angles to the axis of the tube. The tubes shall be free from defects detrimental to practical use.

Higher temperature resistance or capacity corrosion, end up being widely used by petroleum, chemical engineering, boiler, heat exchanger and other power areas. JIS G3462 alloy steel tube is not applicable for heating furnaces and heat exchangers for low temperature service.

Size Array of JIS G3462 Alloy Steel Pipe

• Outer dimension is from 19.05 mm to 168.3 mm.
• Wall thickness ranges from three.0 mm to 14 mm.
• The particular length of such alloy steel tube is 19000 millimeters.

Equivalent steel grade of JIS G3462

Heat treatment of JIS G3462

Advantages

JIS G3462 regulates the allowable size deviation of alloy steel pipes, but JST advanced rolling technology can effectively lessens the deviation range and inside the dimension of alloy steel tube better. We may also supply other sizes of pipes solution . customers’ requirements, but ought to ensure these alloy steel pipes pursue IS G3462 standards.

In production process, there always exists flaw, scar, wrinkling, laceration, rolling burr and other defects on alloy steel tube. JST configures UNICORN ultrasonic joint inspection machine, automatic ultrasonic testing equipment, magnetic flux inspection machine and other styles of inspection machines. They can test our alloy steel pipes.

JST also employs professional surface inspectors who’s able to test the inconspicuous defects on the lining and outside surface of alloy steel tubes. As mentioned by the defect characteristics, perform polishing, removal, repair when a series of processes.