ASTM A335 Seamless Ferritic Alloy Steel Pipe High-Temperature Service

Instruction

ASTM A335 Seamless Ferritic Alloy Steel Pipe for High-Temperature Service

 

ASTM A335 is a widely used specification for seamless ferritic alloy steel pipe intended for high-temperature service. This specification covers a variety of grades and sizes to cater to the demanding conditions of elevated temperatures and corrosive environments. The ASTM A335 standard ensures that these pipes exhibit excellent strength, durability, and resistance to high temperatures.

 

Material and Specification
The ASTM A335 specification outlines the requirements for seamless ferritic alloy steel pipes intended for high-temperature service. The material grades covered by this specification are designated with a "P" prefix, followed by the numerical designation of the grade (e.g., P5, P9, P11, P22, etc.).

 

Here is an overview of the material and specification details:

Specification	ASTM A335
Material	Seamless Ferritic Alloy Steel
Application	High-Temperature Service
Grades	P5, P9, P11, P22, P91, and more
Sizes Range	1/8" - 24" (10.3mm - 610mm)
Wall Thickness	SCH 20, SCH 40, SCH 80, SCH 160, SCH XXS, and custom thicknesses

 

Chemical Composition
The chemical composition of ASTM A335 seamless ferritic alloy steel pipes varies depending on the specific grade. The composition is carefully controlled to ensure the desired mechanical properties and resistance to high-temperature environments.

 

Here is a general overview of the chemical composition requirements for some common grades:

Grade	C	Mn	P	S	Si	Cr	Mo	V
P5	0.15	0.30-0.60	0.025	0.025	0.50	4.00-6.00	0.45-0.65	-
P9	0.15	0.30-0.60	0.025	0.025	0.25-1.00	8.00-10.00	0.90-1.10	-
P11	0.05-0.15	0.30-0.60	0.025	0.025	0.50-1.00	1.00-1.50	0.44-0.65	-
P22	0.05-0.15	0.30-0.60	0.025	0.025	0.50	1.90-2.60	0.87-1.13	-
P91	0.08-0.12	0.30-0.60	0.020	0.010	0.20-0.50	8.00-9.50	0.85-1.05	0.18-0.25

 

Mechanical Properties
The mechanical properties of ASTM A335 alloy steel pipes are crucial for ensuring their reliability and performance under high-temperature conditions. The requirements for tensile strength, yield strength, and elongation vary with the different grades.

 

Here are the typical mechanical properties for selected grades:

Grade	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation (%)
P5	≥ 415	≥ 205	≥ 30
P9	≥ 415	≥ 220	≥ 30
P11	≥ 415	≥ 205	≥ 30
P22	≥ 415	≥ 205	≥ 30
P91	≥ 585	≥ 415	≥ 20

 

Steel Grade and Application
The ASTM A335 specification includes a range of steel grades designed to withstand high-temperature environments while maintaining their mechanical properties. Each steel grade is tailored to specific applications, ensuring optimal performance and reliability.

Steel Grade	Application
P5	Power generation, petrochemical industries
P9	Power generation, chemical industries
P11	Petrochemical industries, refineries
P22	Aerospace, nuclear, and chemical industries
P91	High-temperature service, power generation

In conclusion, ASTM A335 seamless ferritic alloy steel pipes are designed to excel in high-temperature environments, offering a combination of strength, corrosion resistance, and thermal stability. These pipes find applications in various industries where reliable performance under extreme conditions is paramount. The specification provides a range of grades, each with its own chemical composition and mechanical properties to suit specific needs, making them a versatile choice for critical operations.