ASTM A 312 304 Stainless Steel Tubes

ASTM A312 / ASME SA312 Standard Scope

The standard specifications include seamless, straight seam welded and heavily cold welded austenitic stainless steel tubing for high temperature and general corrosive service. There are several grades in this standard, and each steel grade shall confirm to the required chemical composition of C, Mn, P, S, Si, Cr and Cr, Ni, Mo, etc. All the pipes shall be furnished in the heat-treated condition in accordance with the required heat treating temperature and cooling/testing requirements. And also need to comply to the required tensile strength and yield strength.

Heat Treatment Methods

ASTM A312 stainless steel pipes shall be furnished in heat treatment condition comply to table 2 of ASTM A312. In case of seamless types, immediately following hot forming while the temperature of the pipes is not less than the minimum solution treatment temperature specified in this table, pipes shall be individually quenched in water or rapidly cooled by other means (direct quenched).

B: Minimum, unless otherwise stated

C: Quenched in water or rapidly cooled by other means, at a rate sufficient to prevent reprecipitation of carbides, as demonstrable by the capability of pipes. heat treated by either separate solution annealing or by direct quenching, of passing Practices A262, Practice E. The manufacturer is not required to run the test unless it is specified on the purchase order (see Supplementary Requirement S7). Note that Practices A262 requires the test to be performed on sensitized specimens in the low-carbon and stabilized types and on specimens representative of the as-shipped condition for other types. In the case of low-carbon types containing 3% or more molybdenum, the applicability of the sensitizing treatment prior to testing shall be a matter for negotiation between the seller and the purchaser.

Mechanical Test

Mechanical test including heat treated condition, Transverse or Longitudinal Tension Test or Flatten Test.

Transverse or Longitudinal Tension Test

For lots of not more than 100 pipes, one specimen shall be taken for tensile testing. For lots of more than 100 pipes, two specimens shall be taken from two pipes for tensile testing.

Flatten Test

For material heat treated in batch furnace, (by quenching after hot forming or in a batch-type furnace equipped with recording pyrometers and automatically controlled within a 30℃ or less range) 5% of steel pipe should be taken from each heat treated lot for flattening test.

For material heat treated in the continuous furnace, sufficient number of pipe to constitute 5% of the lot, but in any case not less than 2 lengths for flattering test.

Pipe Process of ASME SA312 304 Stainless Steel Seamless tube / ASTM A312 304 Stainless Steel Seamless Pipes

Round Bar → Inspection & Analysis → Cut to Length → Coutering → Peel → Heating → Perforation → Inspection of Size → Pickling → Inspection of Surface → Lubricating  → Cold-Drawing(Cold-Rolling) → Degreasing → Annealing→ Straightening → Cut → Corp End Cutting off → Pickling/Passivating → Final Inspection( UT/ET TEST or Hydrostatic Test) → Marking → Packing → Shipping

Chemical Composition of ASME SA312 304 Steel tube / ASTM A312 304 Stainless Steel tubes:

Standard

Types Chemical Composition(%)

Steel Name

Steel Number

c

Si

Mn

P

S

Cr

Mo

Ni

Al

Cu

Nb

Ti

V

Cr+Cu +Mo+Ni

ASTM A 312/ ASME SA312

304

/

≤0.08

≤0.75

≤2.0

≤0.045

≤0.030

18.00 -20.00

8.0  -11

 

Mechanical Properties of ASME SA312 304 Steel tube / ASTM A312 304 Stainless Steel tubes:

Standard	Grade
	Steel Name	Steel Number	Yield Strength			Tensile Strength	Elongation(%)		hardness
			( Mpa) min.			(Mpa) min.			HRB		HB
ASTM A 312/ ASME SA312							50MM	Transverse			0℃
	304	/	205			515	≥25		92		201

 

 

Grade Specifications of ASME SA312 304 Steel tube / ASTM A312 304 Stainless Steel tubes:

Standard	Steel Name	UNS No.	Old British		Euronorm		Swedish SS	Japanese
ASTM A 312 /  ASME SA312			BS	EN	No.	Name		JIS
	304	S30400	304S31	58E	1.4301	X5CrNi18-10	2332	SUS 304