304H Stainless Steel Pipe

DESCRIPTION

304H is an austenitic stainless steel, which has 18-19% chromium and 8-11% nickel with a maximum of 0.08% carbon. 304H stainless steel pipes are the most versatile and widely used pipes in the stainless steel family. They exhibit excellent corrosion resistance, tremendous strength, high ease of fabrication, and outstanding formability. Hence, are used for a wide variety of home and commercial applications. 304H stainless steel has a controlled carbon content of 0.04 to 0.10. This provides enhanced high temperature strength, even above 800o F. Compared to 304L, 304H stainless steel pipes have greater short term and long term creep strength. Also, they are more resistant to sensitization than 304L.

304H STAINLESS STEEL PIPE PROPERTIES

Mentioned below are the key characteristics of 304H stainless steel pipes offered by Arch City Steel & Alloy:

Heat Resistance:

  • Suitable for high temperature applications, as it offers higher strength at temperatures above 500° C and up to 800° C

  • Grade 304H offers good oxidation resistance in intermittent service to 870° C and in continuous service to 920° C

  • Becomes sensitized in the temperature range of 425-860° C; hence not recommended if aqueous corrosion resistance is required.

Corrosion Resistance:

  • Good resistance to corrosion in oxidizing environments, and moderately aggressive organic acids due to the presence of chromium and nickel respectively

  • Performs uniformly in most corrosive environments

  • May show lower corrosion rate compared to higher carbon grade 304.

Weldability:

  • Readily welded by most standard processes.

  • May be required to anneal after welding

  • Annealing assists in restoring the corrosion resistance lost by sensitization.

Processing:

  • Recommended working temperatures of 1652-2102° F
  • Pipes or tubes should be annealed at 1900° F
  • Material should be water quenched or rapidly cooled
  • 304H grade is quite ductile and forms easily
  • Cold forming helps increase strength and hardness of grade 304H
  • Cold forming may make alloy slightly magnetic

Machineability:

  • Best results are achieved at slower speed, good lubrication, heavier feeds, and sharp tooling

  • Subject to work hardening and chip breaking during deformation.

Applications of Grade 304H Stainless Steel Pipes

Some examples of applications that grade 304H is commonly used for includes:

  • Petroleum refineries
  • Boilers
  • Pipelines
  • Heat exchangers
  • Condensers
  • Steam exhausts
  • Cooling towers
  • Electric generation plants
  • Occasionally used in fertilizer and chemical plants

CHEMICAL COMPOSITION

Typical Chemical Composition % (max values, unless noted)
Grade Cr Ni C Si Mn P S N
304H min: 18.0
max:20.0		 min: 8.0
max: 10.5		 min: 0.04
max:0.10		 0.75
max		 2.0
max		 0.045
max		 0.03
max		 0.10
max