ASTM A335 P91 Alloy Pipe

A335 is often called chrome moly pipe because of the chemical makeup of Molybdenum (Mo) and Chromium (Cr). Molybdenum increases the strength of steel as well as the elastic limit, resistance to wear, impact qualities, and hardenability. Moly increases the resistance to softening, restrains grain growth and makes chromium steel less susceptible to embrittlement. Moly is the most effective single additive that increases high temperature creep strength. It also enhances the corrosion resistance of steel and inhibits pitting. Chromium (or chrome) is the essential constituent of stainless steel. Any steel with 12% or more Chrome is considered stainless. Chrome is virtually irreplaceable in resisting oxidation at elevated temperatures. Chrome raises the tensile, yield, and hardness at room temperatures. The composition chrome moly alloy steel pipe makes it ideal for use in power plants, refineries, petrochemical plants. Heubach Steel Supply stocks a full range of the following A335 pipe grades:

• Grades: P-5, P-9, P-11, P-22, and P-91

Sizes:

• NPS 1/4' to NPS 48'
• Wall Thickness - Schedules 40 through 160, STD, XS, XXS.

ASTM A335/ASME SA335 P91 High Pressure Steel Pipe Chemistry Composition

C, %	Mn, %	P, %	S, %	Si, %	Cr, %	Mo, %	V, %	N, %	Ni, %
0.08-0.12	0.3-0.6	0.02 max	0.01 max	0.2-0.5	8.0-9.5	0.85-1.05	0.18-0.25	0.03-0.07	0.4 max

ASTM A335/ASME SA335 P91 High Pressure Steel Pipe Mechanical Properties

Tensile Strength , MPa	Yield Strength, MPa	Elongation, %	Hardness, HB
585 min	415 min	20 min	250 max

End User:

• P11 for power generation, petroleum, and other high temperature services
• P22 for power generation, petroleum, and other high temperature services
• P5 for petroleum
• P9 for petroleum
• P91 for power generation
• P92 for power generation
• P1 for boiler replacement and repair