P1 Alloy Steel Seamless Pipe

What is A335 P1 alloy pipe

‌ASTM A335 P1 Alloy Pipe‌ is a seamless ferritic alloy steel pipe standardized by the American Society for Testing and Materials (ASTM), specifically designed for high-temperature applications. This standardized pipe belongs to the chromium-molybdenum alloy steel series and is primarily used in high-temperature, high-pressure pipeline systems.

‌Heat Treatment Requirements for P1 Grade:‌

‌Delivery Condition:‌

May be supplied in one of the following states: ‌fully annealed‌, ‌isothermally annealed‌, or ‌normalized and tempered‌.

When delivered in the normalized and tempered condition, ‌the minimum tempering temperature for P1 shall be 650°C‌.

‌For pipes manufactured via hot rolling or cold drawing:‌

The manufacturer may perform final heat treatment at ‌650–705°C‌ as an alternative to the treatments specified above.

 

Chemical Composition of ASTM A335 Gr. P1 Pipes

 

Mechanical properties of ASTM A335 Gr. P1 Pipes

 

ASTM A335 P1 Pipe Equivalent

ASTM	ASME	JIS G 3458	UNS	BS	DIN	ISO	ABS	NK	LRS
A335 P1	SA335 P1	STPA 12	K11597	-	17175 15Mo3	2604 II TS26	ABS 6	KSTPA 12	-
					17177 15Mo3	2604 III TW26

 

Comparison with P2 Grade

Parameter	P1	P2
Cr Content	0.44-0.65%	0.50-0.81%
Mo Content	0.44-0.65%	0.44-0.65%
Heat Treatment	Normalizing + Tempering	Coarse Grain Melting Process

 

Comparison with P5 Grade

Parameter	P1	P5
Cr Content	0.44-0.65%	4.00-6.00%
Mo Content	0.44-0.65%	0.45-0.65%
Service Temperature	≤550°C	≤600°C

 

Comparison with P9 Grade

Parameter	P1	P9
Cr Content	0.44-0.65%	8.00-10.00%
Mo Content	0.44-0.65%	0.90-1.10%
Max Working Temp.	550°C	650°C

 

‌ASTM A335 P1 alloy pipes must pass rigorous quality inspections, including:‌

‌Spectroscopic analysis‌ to verify chemical composition

‌Tensile testing‌ to evaluate mechanical properties

‌Ultrasonic/eddy current testing‌ to screen for internal defects

‌Hydrostatic testing‌ to confirm sealing integrity

 

Packaging and shipping