PASSIVATION OF STAINLESS STEELS

PASSIVATION   is the treatment of the surface of corrosion-resistant steels (i.e. 200, 300, and 400 series stainless steels) with certain agents which will remove surface contaminants and produce a surface condition which is resistant to corrosive action. This process is widely used to clean stainless steels and provides a higher degree of corrosion resistance. Finished parts retain the dimension they had prior to treatment.

Stainless steels' passivity is primarily due to the ability of its chromium content to build up an oxide film. The oxide film provides protection from corrosion and chemical attack. This film is normally destroyed or damaged during the manufacturing process. It is common practice to restore the damaged oxide film layer by a passivation treatment.

BLACK PASSIVATION (BLACK PASSIVATE)   is better known as "Black Oxide Class 2, Black Oxide Class 3, or Black Oxide Class 4" for corrosion resistant steel alloys. It is a conversion coating that produces a uniform, attractive, and non-reflective black finish on stainless steels. It provides a permanent black color with exceptional strength and elasticity. The finish does not chip, peel, craze, or rub off and provides good resistance to wear and abrasion. The coating reduces friction of moving parts, preventing galling and scoring. Improved corrosion resistance is obtained and there is a negligible .00001 - .00003 dimensional change.



APPLICATIONS:   Passivation has a wide range of applications for military, commercial and consumer stainless steel products throughout the world. It is used extensively on aircraft and automotive parts, ball bearings, bolts, camera components, cutting tools, fasteners, firearms, gages, gears, instruments, military equipment, screw machine products, stampings, tools and many other applications.

SPECIFICATIONS:   Acton Metal Processing Corp. provides PASSIVATION TREATMENTS FOR STAINLESS STEELS that conform to the following specifications:

AMS-2700, Method 1, Type 1  Low temperature nitric acid with sodium dichromate  	 
AMS-2700, Method 1, Type 2  Medium temperature nitric acid with sodium dichromate 	 
AMS-2700, Method 1, Type 3  High temperature nitric acid with sodium dichromate 	 
AMS-2700, Method 1, Type 4  40% nitric acid for free machining steels 	 
AMS-2700, Method 1, Type 6  Low temperature nitric acid 	 
AMS-2700, Method 1, Type 7  Medium temperature nitric acid 	 
AMS-2700, Method 1, Type 8  High temperature, high nitric acid concentration 	 
  	  	 
SP-112 	                    Treating stainless steel parts to prevent corrosion 	 
  	  	 
MIL-DTL-14072 Finish No. E-300  Passivate per ASTM A380 	 
  	  	 
ASTM A967 Nitric 1 	Chemical Passivation Treatment - medium temperature with 
                        sodium dichromate
 	 
ASTM A967 Nitric 2 	Chemical Passivation Treatment - low temperature nitric 
                        acid
 	 
ASTM A967 Nitric 3 	Chemical Passivation Treatment - medium temperature nitric 
                        acid
 	 
ASTM A967 Nitric 4 	Chemical Passivation Treatment - high temperature, high 
                        nitric acid concentration 	 
  	  	 
AMS-QQ-P-35, Type II 	Passivation Treatment - medium temperature with sodium 
                        dichromate
 	 
AMS-QQ-P-35, Type VI 	Passivation Treatment - low temperature nitric acid
 	 
AMS-QQ-P-35, Type VII 	Passivation Treatment - medium temperature nitric acid
 	 
AMS-QQ-P-35, Type VIII 	Passivation Treatment - high temperature, high nitric 
                        acid concentration 	 
  	  	 
QQ-P-35, Type II 	Passivation Treatment - medium temperature with sodium 
                        dichromate
 	 
QQ-P-35, Type VI 	Passivation Treatment - low temperature nitric acid 	 
QQ-P-35, Type VII 	Passivation Treatment - medium temperature nitric acid 	 
QQ-P-35, Type VIII 	Passivation Treatment - high temperature, high nitric 
                        acid concentration 	 
  	  	 
ASTM A380 	        Standard Practice for Cleaning, Descaling, and Passivation 
                        of Stainless Steel Parts, Equipment, and Systems 	 
  	  	 
MIL-S-5002 	        Surface Treatments And Inorganic Coatings For Metal 
                        Surfaces Of Weapons Systems 	 
  	  	 
MIL-STD-171E Finish No. 5.4.1 	Clean and passivate, QQ-P-35 (Clean ASTM A380)

Additionally, our passivation processes meet or exceed the custom specifications of most major U.S. companies. If you have a question about a particular passivating specification or have a custom specification, please call us and ask.

CAPABILITIES:   Our facilities and highly skilled technicians are able to meet your passivating needs today. We can accommodate most any job size from small to large. Acton Metal Processing Corp. is your source for cost-effective clear passivating or black passivating.


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Acton Metal Processing Corp. provides many metal finishes including:

 
 
 
 
 
 


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