Primary tabs
Nitric Acid 68%
Extra pure NITRIC , removes iron residue & forms an oxide layer that boosts the corrosion resistance of the stainless steel intended to improve the corrosion resistance of parts made from austenitic, ferritic and martensitic corrosion-resistant steels of the 200, 300 and 400 series and precipitation hardened corrosion-resistant steels.
High carbon, high chromium martensitic 440C grades which are selected for high hardness and resistance may be exempt from passivation treatments at the discretion of the procuring activity.
PRECAUTION :
1> Loose iron particles or other foreign particles must be removed or they will appear as rust or stain spots. may become smeared over or imbedded into the surface of corrosion-resistant steel parts.
2> DO avoid chlorides that, in excess, can cause a harmful flash attack. When possible, use only a good grade of water containing less than about 50 parts per million (ppm) of chlorides. Tap water is usually adequate, and in some cases up In several hundred ppm chlorides can be tolerated.
Chlorides: are present in many cleaning agents. This entails risk of pitting corrosion of stainless steel. If a cleaner containing chlorine, chlorides, bleaches orhypochlorites is
Transparent, colourless or yellowish corrosive liquid. A strong oxidizing agent that will attack allmost all metals.
Hazard: Dangerous fire risk in contact with orgenic materials. Highly toxic by inhalation, corrosive to the skin and mucous membrance. Uses : Orgenc synthesis (dyes, drugs,explosives, cellulose nitrate, nitrate salts ), photoengraving, etching steel.
Passivation Treatments
• Grades with at least 16% chromium (except free machining grade such as 303):
20-50% nitric acid, at room temperature to 40oC for 30-60 minutes.
• Grades with less than 16% chromium (except free machining grades such as 416):
20-50% nitric acid, at room temperature to 40oC for 60 minutes.
• Free machining grades such as 303, 416 and 430F:
20-50% nitric acid + 2-6% sodium dichromate, at room temperature to 50oC for 25 40 minutes
Pickling Treatments
• All stainless steels (except free machining grades):
8-11% sulphuric acid, at 65 to 80oC for 5-45 minutes.
• Grades with at least 16% chromium (except free machining grades):
15-25% nitric acid + 1-8% hydrofluoric acid, at 20 to 60oC for 5-30 minutes.
• Free machining grades and grades with less than 16% chromium such as 303, 410
| PROBLEM | CLEARING AGENT | COMMENTS |
| Rust and other corrosion products. Embedded or adhering "free iron | Very light rust stain can be removed by 10% nitric acid. More significant rust or embedded iron will require picking. See also previous sections on Passivating and Picking. Sand or glass-bead blasting is another option | Wear PPE as appropriate. Afterwards rinse well with clean water. Mix in acid-proof container, and be very careful with the acid, (See Precautions for acid cleaners) |
| Routine cleaning of boat fittings. | Frequent washing down with fresh water. | Recommended after each time the boat is used in salt water. |
| Cooking pot boiled dry. | Remove burnt food by soaking in hot water with detergent, baking soda or amonia. | Afterwards clean and polish. with a mild abrasive if necessary. See comments re steel wool. |
| Dark oxide from welding or heat treatment. | "Picking Paste" or picking solutions given on previous page. | Must be careful rinsed, and use care in handling (see Precautions for acid cleaners). |
| Scratches on polished (satin or brushed) finish. | Slight scratches - use impregnated nylon pads. Polish with polishing wheel dressed with iron-free abrasive for deeper scratches. Follow polish lines. Then clean with soap or detergent as for routine cleaning | Do not use ordinary steel wool - iron particles can become embedded in stainless steel and cause further surface problems. Stainless steel and "Scotchbrite" scouring pads are satisfactory. |
| PROBLEM | CLEARING AGENT | COMMENTS |
| Routine cleaning All finishes | Soap mild detergent and water. (preferably warm) | Sponge, rinse with clean water, wipe dry if necessary. Follow polish lines. |
| Fingerprints All finishes | Soap warm water or organic solvent (eg acetone, alchol, methylated spirits) | Rinse with clean water and pipe dry. Follow polish lines. |
| Stubborn stains and discoloration. All finishes. | Mild cleaning solutions. Ensure any properietary cleaners state compatibility with stainless steel. Phpsphoric acid cleaners may also be effective | Use rag, sponge or fibre brush (soft nylon or natural bristle. An old toothbrush can be useful). Rinse well with clean water and wipe dry. Follow polish lines. |
| Lime deposits from hard water. | Solution of one part vinegar to three parts water. | Soak in solution then brush to loosen. Rise well with clean water. |
| Oil or grease marks. All finishes. | Organic solvents (eg. acetone, alchol, methylated spirits, proprietary "safety solvents"). Baked-on grease can be softened beforehand with ammonia |
Clean after with soap and water, rinse with clean water and dry. Follow polish lines |
| PROBLEM | CLEARING AGENT | COMMENTS |
| Rust and other corrosion products. Embedded or adhering "free iron | Very light rust stain can be removed by 10% nitric acid. More significant rust or embedded iron will require picking. See also previous sections on Passivating and Picking. Sand or glass-bead blasting is another option | Wear PPE as appropriate. Afterwards rinse well with clean water. Mix in acid-proof container, and be very careful with the acid, (See Precautions for acid cleaners) |
| Routine cleaning of boat fittings. | Frequent washing down with fresh water. | Recommended after each time the boat is used in salt water. |
| Cooking pot boiled dry. | Remove burnt food by soaking in hot water with detergent, baking soda or amonia. | Afterwards clean and polish. with a mild abrasive if necessary. See comments re steel wool. |
| Dark oxide from welding or heat treatment. | "Picking Paste" or picking solutions given on previous page. | Must be careful rinsed, and use care in handling (see Precautions for acid cleaners). |
| Scratches on polished (satin or brushed) finish. | Slight scratches - use impregnated nylon pads. Polish with polishing wheel dressed with iron-free abrasive for deeper scratches. Follow polish lines. Then clean with soap or detergent as for routine cleaning | Do not use ordinary steel wool - iron particles can become embedded in stainless steel and cause further surface problems. Stainless steel and "Scotchbrite" scouring pads are satisfactory. |
| PROBLEM | CLEARING AGENT | COMMENTS |
| Routine cleaning All finishes | Soap mild detergent and water. (preferably warm) | Sponge, rinse with clean water, wipe dry if necessary. Follow polish lines. |
| Fingerprints All finishes | Soap warm water or organic solvent (eg acetone, alchol, methylated spirits) | Rinse with clean water and pipe dry. Follow polish lines. |
| Stubborn stains and discoloration. All finishes. | Mild cleaning solutions. Ensure any properietary cleaners state compatibility with stainless steel. Phpsphoric acid cleaners may also be effective | Use rag, sponge or fibre brush (soft nylon or natural bristle. An old toothbrush can be useful). Rinse well with clean water and wipe dry. Follow polish lines. |
| Lime deposits from hard water. | Solution of one part vinegar to three parts water. | Soak in solution then brush to loosen. Rise well with clean water. |
| Oil or grease marks. All finishes. | Organic solvents (eg. acetone, alchol, methylated spirits, proprietary "safety solvents"). Baked-on grease can be softened beforehand with ammonia |
Clean after with soap and water, rinse with clean water and dry. Follow polish lines |
| PROBLEM | CLEARING AGENT | COMMENTS |
| Rust and other corrosion products. Embedded or adhering "free iron | Very light rust stain can be removed by 10% nitric acid. More significant rust or embedded iron will require picking. See also previous sections on Passivating and Picking. Sand or glass-bead blasting is another option | Wear PPE as appropriate. Afterwards rinse well with clean water. Mix in acid-proof container, and be very careful with the acid, (See Precautions for acid cleaners) |
| Routine cleaning of boat fittings. | Frequent washing down with fresh water. | Recommended after each time the boat is used in salt water. |
| Cooking pot boiled dry. | Remove burnt food by soaking in hot water with detergent, baking soda or amonia. | Afterwards clean and polish. with a mild abrasive if necessary. See comments re steel wool. |
| Dark oxide from welding or heat treatment. | "Picking Paste" or picking solutions given on previous page. | Must be careful rinsed, and use care in handling (see Precautions for acid cleaners). |
| Scratches on polished (satin or brushed) finish. | Slight scratches - use impregnated nylon pads. Polish with polishing wheel dressed with iron-free abrasive for deeper scratches. Follow polish lines. Then clean with soap or detergent as for routine cleaning | Do not use ordinary steel wool - iron particles can become embedded in stainless steel and cause further surface problems. Stainless steel and "Scotchbrite" scouring pads are satisfactory. |
| PROBLEM | CLEARING AGENT | COMMENTS |
| Routine cleaning All finishes | Soap mild detergent and water. (preferably warm) | Sponge, rinse with clean water, wipe dry if necessary. Follow polish lines. |
| Fingerprints All finishes | Soap warm water or organic solvent (eg acetone, alchol, methylated spirits) | Rinse with clean water and pipe dry. Follow polish lines. |
| Stubborn stains and discoloration. All finishes. | Mild cleaning solutions. Ensure any properietary cleaners state compatibility with stainless steel. Phpsphoric acid cleaners may also be effective | Use rag, sponge or fibre brush (soft nylon or natural bristle. An old toothbrush can be useful). Rinse well with clean water and wipe dry. Follow polish lines. |
| Lime deposits from hard water. | Solution of one part vinegar to three parts water. | Soak in solution then brush to loosen. Rise well with clean water. |
| Oil or grease marks. All finishes. | Organic solvents (eg. acetone, alchol, methylated spirits, proprietary "safety solvents"). Baked-on grease can be softened beforehand with ammonia |
Clean after with soap and water, rinse with clean water and dry. Follow polish lines |
| PROBLEM | CLEARING AGENT | COMMENTS |
| Rust and other corrosion products. Embedded or adhering "free iron | Very light rust stain can be removed by 10% nitric acid. More significant rust or embedded iron will require picking. See also previous sections on Passivating and Picking. Sand or glass-bead blasting is another option | Wear PPE as appropriate. Afterwards rinse well with clean water. Mix in acid-proof container, and be very careful with the acid, (See Precautions for acid cleaners) |
| Routine cleaning of boat fittings. | Frequent washing down with fresh water. | Recommended after each time the boat is used in salt water. |
| Cooking pot boiled dry. | Remove burnt food by soaking in hot water with detergent, baking soda or amonia. | Afterwards clean and polish. with a mild abrasive if necessary. See comments re steel wool. |
| Dark oxide from welding or heat treatment. | "Picking Paste" or picking solutions given on previous page. | Must be careful rinsed, and use care in handling (see Precautions for acid cleaners). |
| Scratches on polished (satin or brushed) finish. | Slight scratches - use impregnated nylon pads. Polish with polishing wheel dressed with iron-free abrasive for deeper scratches. Follow polish lines. Then clean with soap or detergent as for routine cleaning | Do not use ordinary steel wool - iron particles can become embedded in stainless steel and cause further surface problems. Stainless steel and "Scotchbrite" scouring pads are satisfactory. |
| PROBLEM | CLEARING AGENT | COMMENTS |
| Routine cleaning All finishes | Soap mild detergent and water. (preferably warm) | Sponge, rinse with clean water, wipe dry if necessary. Follow polish lines. |
| Fingerprints All finishes | Soap warm water or organic solvent (eg acetone, alchol, methylated spirits) | Rinse with clean water and pipe dry. Follow polish lines. |
| Stubborn stains and discoloration. All finishes. | Mild cleaning solutions. Ensure any properietary cleaners state compatibility with stainless steel. Phpsphoric acid cleaners may also be effective | Use rag, sponge or fibre brush (soft nylon or natural bristle. An old toothbrush can be useful). Rinse well with clean water and wipe dry. Follow polish lines. |
| Lime deposits from hard water. | Solution of one part vinegar to three parts water. | Soak in solution then brush to loosen. Rise well with clean water. |
| Oil or grease marks. All finishes. | Organic solvents (eg. acetone, alchol, methylated spirits, proprietary "safety solvents"). Baked-on grease can be softened beforehand with ammonia |
Clean after with soap and water, rinse with clean water and dry. Follow polish lines |
During processing operations such as forming, machining, tumbling and lapping, iron particles or other foreign particles may become smeared over or imbedded into the surface of corrosion-resistant steel parts. These particles must be removed or they will appear as rust or stain spots.
High carbon, high chromium martensitic 440C grades which are selected for high hardness and resistance may be exempt from passivation treatments at the discretion of the procuring activity.
CAS NUMBER 7697-37-2
|
ITEM |
: |
NITRIC ACID ( HNO3 ) |
|
Molecular Weight |
: |
63.01 |
|
Composition |
: |
H 1.60 % NO398.40% |
|
|
||
SPECIFICATION OF PRODUCT |
|
|
|
HNO3CONTENT, WT.% MIN |
: |
62 - 68 % |
|
MINIMUM FREEZING POINT |
: |
5.3OC |
|
IDENTITY |
: |
BY IR Spectrum |
|
APPEARANCE |
: |
CLEAR FUMING NITRIC ACID NOTE : IT IS DECOMPOSED BY LIGHT OR ELEVATED TEMP., BECOMING RED IN COLOUR FROM NITROGEN DIOXIDE. |
|
CARBONISABLE SUBSTANCES |
: |
PASSES THE TEST |
|
COLOUR, MAX |
: |
10 HU |
|
NON VOLATILE MATTER |
: |
0.001% |
|
CHLORIDE CONTENT, PPM, MAX |
: |
0.1 ppm |
|
ORGANIC IMPURITIES |
: |
Passes test |
|
SULPHUR TOTAL AS SULPHATES, PPM, MAX |
: |
0.5 ppm |
|
PHASE |
: |
LIQUID |
Nitric Acid (68%) Safety Data Sheet
|
Chemical Identity
|
|
|
|||||||||||||||||||
|
Physical / Chemical Data
|
|
||||||||||||||||||||
|
Fire / Explosion Hazard Data
|
|
||||||||||||||||||||
|
Preventive Measures
Spills |
|