Chemical Composition Element Specified / Typical Range (wt. %) C ≤0.08 Mn ≤2.00 Si ≤1.00 P ≤0.045 S ≤0.030 Cr 17.0–19.0 Ni 9.0–12.0 Mo — N ≤0.10 Ti ≥5×C; ≤0.70 Fe Balance Note: Values are presented as representative ASTM A182 grade requirements. The applicable standard edition and material certificate govern the final chemical limits.

Mechanical Properties Property Minimum / Requirement Tensile Strength, min. 515 MPa Yield Strength, 0.2%, min. 205 MPa Elongation, min. 30% Hardness As specified by applicable standard / product condition

High-temperature process piping Heat exchangers and thermal equipment Petrochemical and refinery systems Furnace and exhaust components Welded piping exposed to elevated temperatures

Chemical Composition Element Specified / Typical Range (wt. %) C ≤0.08 Mn ≤2.00 Si ≤1.00 P ≤0.045 S ≤0.030 Cr 17.0–19.0 Ni 9.0–12.0 Mo — N ≤0.10 Ti ≥5×C; ≤0.70 Fe Balance Note: Values are presented as representative ASTM A182 grade requirements. The applicable standard edition and material certificate govern the final chemical limits.

Mechanical Properties Property Minimum / Requirement Tensile Strength, min. 515 MPa Yield Strength, 0.2%, min. 205 MPa Elongation, min. 30% Hardness As specified by applicable standard / product condition

High-temperature process piping Heat exchangers and thermal equipment Petrochemical and refinery systems Furnace and exhaust components Welded piping exposed to elevated temperatures

321 Stainless Steel Flange

Grade: 321

Flange types：

Weld Neck (WN); Slip-On (SO); Blind (BL); Socket Weld (SW); Threaded (TH); Lap Joint (LJ); Orifice Flange where specified

Nominal size：

ASME: NPS 1/2–24 under B16.5; large diameter NPS 26–60 under B16.47; EN/JIS/GB/T sizes depend on applicable standard

Pressure rating：

ASME Class 150, 300, 400, 600, 900, 1500, 2500 (availability depends on size/type); EN/GB PN classes; JIS 5K–63K

321 is a titanium-stabilized austenitic stainless steel based on 304 chemistry. Titanium binds carbon and helps reduce chromium carbide precipitation during exposure to elevated temperatures. It is therefore useful for welded components and piping that experience elevated service temperatures. 321 combines good general corrosion resistance with good high-temperature stability and is frequently selected for thermal processing and exhaust-related applications.

Chemical Composition

Element	Specified / Typical Range (wt. %)
C	≤0.08
Mn	≤2.00
Si	≤1.00
P	≤0.045
S	≤0.030
Cr	17.0–19.0
Ni	9.0–12.0
Mo	—
N	≤0.10
Ti	≥5×C; ≤0.70
Fe	Balance

Note: Values are presented as representative ASTM A182 grade requirements. The applicable standard edition and material certificate govern the final chemical limits.

Mechanical Properties

Property	Minimum / Requirement
Tensile Strength, min.	515 MPa
Yield Strength, 0.2%, min.	205 MPa
Elongation, min.	30%
Hardness	As specified by applicable standard / product condition

High-temperature process piping
Heat exchangers and thermal equipment
Petrochemical and refinery systems
Furnace and exhaust components
Welded piping exposed to elevated temperatures

Introduction

Specification

Chemical Composition

Element	Specified / Typical Range (wt. %)
C	≤0.08
Mn	≤2.00
Si	≤1.00
P	≤0.045
S	≤0.030
Cr	17.0–19.0
Ni	9.0–12.0
Mo	—
N	≤0.10
Ti	≥5×C; ≤0.70
Fe	Balance

Note: Values are presented as representative ASTM A182 grade requirements. The applicable standard edition and material certificate govern the final chemical limits.

Mechanical

Mechanical Properties

Property	Minimum / Requirement
Tensile Strength, min.	515 MPa
Yield Strength, 0.2%, min.	205 MPa
Elongation, min.	30%
Hardness	As specified by applicable standard / product condition