Stainless Steel 304 Pipes: What You Need To Know

Stainless Steel 304 Pipes

Stainless Steel (SS) has become the most popular and most used material in the world since its development over 100 years ago. Amongst various grades, 304 is the most widely used grade of stainless steel. It is also commonly known as “A2 stainless steel”. This blog provides you with all the necessary information you might need before using this grade of steel for your work. 

SS 304 Pipes – Pipe made from Stainless Steel 304 (UNS S30400) is an austenitic chromium-nickel alloy. Its principle crystalline structure is austenite which inhibits the steels from being hardened by heat treatment and renders them essentially non-magnetic.

Characteristics of SS 304 Pipes

This grade of pipes possess the following qualities:

  • Corrosion Resistance: 304 stainless steel pipes are resistant to a wide range of atmospheric conditions as well as a variety of corrosive media. In heated chloride environments, it is prone to pitting and crevice corrosion, as well as stress corrosion cracking above (approximate) 60 °C.
  • Cryogenic Resistance: At cryogenic temperatures, austenitic stainless steels such as 304 become “tough” and can be classified as “cryogenic steels”. They are suitable for sub-zero ambient temperatures, as well as sub-arctic and arctic applications and locations, typically down to -40°C.
  • Heat Resistance: In intermittent service, grade 304 pipes have good oxidation resistance up to 870 °C and in continuous service to 925 °C.  

SS 304 often performs well in temperatures that fluctuate between these extremes (-40°C to 925°C).

  • Weldability: SS 304 Pipe has outstanding weldability. It can be welded using any standard fusion method, with or without filler metals. Although appropriate post-weld clean-up is recommended, post-weld annealing is often not required to restore 304’s corrosion resistance.
  • Formability: SS 304 is easier to draw and form due to its lower strength and work hardening rate.
  • Cold Working: Austenitic steels are hardened by cold working only as they do not have enough carbon to be hardened by heat treatment. Cold working produces high hardness and strength.
  • High Strength: 

Types of Pipes

  1. Based on shapes – The stainless steel 304 pipes are available in various shapes such as:-
  • Round
  • Square
  • Rectangle
  1. Based on Manufacturing – SS 304 pipes can be distinguished based on the way they are manufactured.
  • Welded – Welded pipe is a steel pipe made by crimping and welding a steel plate or strip steel.
  • Seamless – Seamless pipe is made from a billet that has been extruded, drawn and heated over a shape until it becomes a hollow tube. 

Applications of SS 304 Pipes

These pipes are extensively used in various industries such as;

  • Chemicals
  • Food and Beverage
  • Dyeing 
  • Mining
  • Pharmaceutical
  • Domestic tools industry
  • Architectural
  • Cryogenics
  • Dairy
  • Marine

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