Cast Stainless Steel CN7M

Cast Stainless Steel CN7M


Type CN7M covers a group of related complex Fe-Ni-Cr-Cu alloys that contain more nickel than chromium. The high nickel content, together with the added elements molybdenum and copper, give these alloys especially good resistance to sulfuric acid and many reducing chemicals. Among the alloys included in this type designation, alloy 20 is produced in greatest quantity.Whereas the chromium predominant alloys have poor or no resistance to hydrochloric acid, type CN7M has good resistance to dilute acid and hot chloride salt solutions. The alloy also will resist nitric acid satisfactorily.

Chemical Composition

ASTM A351  A743  A744, DIN 1.4500, 2.4660 GX7NiCrMoNb25-20

Equivalent Grades


Melting Point(oC)

For maximum corrosion resistance, castings of CN7M alloy should be heated to 2050°F (1121°C) minimum, and

then quenched in water, oil or air to ensure complete solution of carbides


Heat Treatment


Hardness (HB)


Welding Electrode


Welding Preheating(oC)

Gas Porosity

Common Possible Casting Defects



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