ASTM A182 / A182M – 12a Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service.
ASTM A182 is a martensitic stainless steel. The additions of Nickel and Molybdenum, which gives it excellent sub zero notch ductility, superior to other standard 13 Cr, 410 and 420 Mod martensitic stainless steels.
UNS S41500 steel is air hardening, with little danger of thick sections cracking during heat treatment.
In addition to limiting the maximum hardness allowed to 23 HRC max, NACE MR0175 imposes heat treatment temperature restrictions.
The weldability and corrosion resistance of ASTM A182 are also excellent, being extensively used in the manufacture of Valve Bodies, Flanges, Seats, Gates, Tubulars, etc.
ASTM A182 specifies a minimum 0.2 PS value of 95 KSI. This NACE approved grade is limited to 75 KSI because of the hardness restriction.
This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
Chemical Requirements of ASTM A182 material (Composition, %, max)
Note: composition of Cu, N, V, Co are none or few.
Mechanical Requirements  of ASTM A182 material