What is Nital etch used for?
Nital Etch, also known as Surface Temper Etch and Temper Etch, is a non-destructive test that is used to determine if overheating has occurred in a part (after final heat treat) by abusive machining or grinding that will adversely affect the required properties of the part in question.
How do you make 2 Nital?
Nital is easily made by simply mixing nitric acid and methanol in the desired proportions, typically 1-10 % by volume nitric acid into methanol depending on whether a microetch or a macroetch is desired. Remember, alway add acid to the methanol (or water, as the case may be), and never the other way around.
What is Nital etch made of?
Nital is a solution of nitric acid and alcohol commonly used for etching of metals. It is especially suitable for revealing the microstructure of carbon steels. The alcohol can be methanol, ethanol or methylated spirits. Mixtures of ethanol and nitric acid are potentially explosive.
What are the types of etchant solutions?
The authors prefer to use alcoholic ferric chloride as aqueous solution etches fast and often stains. Alcoholic Ferric Chloride 240 ml ethanol, 60 ml hydrochloric acid and 20 g ferric chloride. This is the most common etchant used by the authors.
How do you use nital etchant?
Nital, a Nitric Acid – Alcohol mixture, is the etchant commonly utilized with common irons and steels. Nital is dripped onto the specimen using an eye-dropper or cotton swab. Ten seconds to one minute is usually sufficient for proper etching depending on sample and nital concentration.
Which etchant is used for mild steel?
IRON & CARBON STEEL ETCHANTS
|Type of Steel:||Etchant to Use:|
|Carbon steels and mild steels in general||Nital|
|Cast irons & tool steels (most)||Nital|
|Carburized or heat-treated carbon steels||First Picral then Nital|
|Others||See this list|
Is Nital flammable?
Explosion: Above flash point, vapor-air mixtures are explosive within flammable limits noted above. Vapors can flow along surfaces to distant ignition source and flash back. Sealed containers may rupture when heated.
What etchant is used for brass?
|Copper No. 1: Nitric acid Distilled water||125 ml 125 ml||Common etchant for copper and copper alloys such as brass and bronze|
|Copper No. 2: Distilled water Ferric chloride Hydrochloric acid||200 ml 10 gm 50 ml||Brasses, bronzes, aluminum brass, alpha -phases in brass|
Which etchant is used for steel?
Nital, a Nitric Acid – Alcohol mixture, is the etchant commonly utilized with common irons and steels. Nital is dripped onto the specimen using an eye-dropper or cotton swab.