INTRODUCTION:

FRANK SCUFFRITE is a Non- Polluting, concise, Liquid Nitriding System developed for the ever demanding applications of Nitriding. It is the solution for noval, dependable, stable, simple fool Proof, yet effective Heat Treatment .

APPLICATIONS:

Though the area of application is very fastly expanding , few of the contemporary applications Are:

AUTOMOBILE :

Crank shafts, carm shafts, Rocker shafts , Tappets, Liners, splined shafts, Oil fuel & water feed pump gears etc.

MACHINE TOOL :

Spindles, beds, guides, slides, bushes, worms, pinions, cutting tools, Tool holders, dies, punches etc.

ADVANTAGES :

1. The Nitriding potential being high, it results in high surface hardness coupled with excellent resistance to scuffing and fatigue in short time.

2. Being Non-Pollutive, it is very safe in operation and is an ideal replacement For traditional liquid nitriding involving hazardous and polluting salts.

3. Very easy to operate and controlled by simple tests requiring no chemical Knowledge.

SALTS REQUIRES:

1. Frank Epsilon ---- Nitriding Salt
2. Frank Nirogen ---- Regenerator
3. Frank Endurox ---- Backening Salt
4. Potassium Sulphide ---- Catalyst.

PROCESS :

OPERATION:

The Process consists of treating the components in an aged aerated bath at a temperature of 560-570°C for 90 to 120 minutes and then quenching in suitable medium. ( Water, Oil or Air Cool)

PRINCIPLE :

1. NITRIDING

The active Nitriding agents are Nirogen which are continuously produced in the bath as under:

(1) 4 CNO⁻ → CO3 ² ⁻ + CO + 2 CN⁻ + 2 N

(2) 2 CNO ⁻ + O₂ → CO 3²⁻ + CO + 2 N

2.REGENERATOR

CNO ⁻ = 36 ±2%

CO ⁻₃² = 19 ± 2%

S ² ⁻ = 2 TO 5 PPM

CN ⁻ = Less than 1%

CONTROL :

The bath control is done by simple periodical tests for percentage of cyanate, sulphide and Carbonate in the bath and if necessary, required additions of Nirogen is done.

EQUIPMENTS:

1. Pot 2. Aerator ( Ring with air compressor Lines ) 3. Desludger

NITRIDING SALT MATERIAL OF CONSTRUCTION:

Pot, Aerator, Desludger, jigs & Fixtures : Any Ferritic Chromium steel of type AISI 430, Titanium Pots will be an excellent choice. For Endurox baths, the Pot can be of AISI 304 / 310.

HEAT SYSTEM :

FRANK Scuffrite can be operated like any other salt bath operation but heating is to be done By electricity. Accurate temperature maintenance has to be ensured by installing suitable Periodically calibrated controllers.

VENTILATION :

As common to salt bath practice, the shop floor should be ventilated and provision of a powerful Exhaust system is necessary.

PROCESS :

1) Filling the Pot to working level with Frank Epsilon.

2) Heating the salt by uniform indirect heating to 560°C

3) Agitating the bath continuously with clean, dry air cooled by flow meter at the rate of 75 Litres

per hour for every 100 kgs, of bath capacity for about 24 hours to age the bath.

4) Checking the bath Chemistry : Adjusting the cyanate content with slow additions of

Frank Nirogen. Filling the Endurox bath and raising the temperature slowly by 360-390°C.

PROCESS CONTROLS:

1.Temperature to be maintained strictly between 560-570°C

2.Aeration to be continuously provided and flow to be controlled depending on the cyanate drop.

( This again depends on volume of the bath, components treated and Potassium sulphide additions)

3.Desludging the bath at regular intervals. The sludge, if allowed to interfere, will affect the

uniformity, Quality, finish of the treated components.

4.Potassium sulphide is to be added at regular intervals.

NOTE :Frank Nirogen additions should be gradual as it will be followed by an evolution of Ammonia which is a strong smelling and irritating. Operators should wear goggles and respiratory masks at the time of additions.

METALLURGY OF SCUFFRITE

1. SUPERFICIAL HARDNESS :

The surface hardness of the Nitrided components depends on the alloying composition of steel..

Sl.No	Material	Hardness achieved After 90 Minutes
1.	EN 8 ( H & Td )	420 HVI
2.	EN 19	560 HVI

2. SURFACE FINISH:

After the Nitriding treatment, the components have a gray colour while after Frank Endurox treatment ( Post Treatment) the components get an attractive, protective dark black finish. The details on which can be obtained on request.

3. CHANGE IN DIMENSION:

The treatment gives rise to a slight growth of the components depending on the composition Of the material.

For plain carbon steel ( EN 8 type ) treated for 90 minutes the average increase will be 6-8 Microns.

While Alloy Steels treated for the same time will increase by 2-4 microns.

4. COMPOUND & DIFFUSION LAYERS:

Being highly activated, Epsilon baths give a very compact compound layer to a depth of 10-15 microns containing mainly Epsilon Nitrides .

Diffusion layer is obtained to a depth of 0.2 to 0.4 mm which stabilizes the Epsilon Nitrides and increases the fatigue resistance considerably.

5.POST TREATMENT :

After Nitriding various finishing processes can be applied on the Nitrided surfaces. They include Lapping,Polishing, Honing etc.

6.TECHNICAL PACKAGE:

Frank Epsilon systems are very easy to install and operate and does not call for qualified operators. Frank’s Services for installation and staff training can be obtained on request.

FRANK SCUFFRITE

BATH DIAGNOSIS

REQUIREMENTS:

A) APPARATUS:

1. Chemical Balance ( With Weight Box Set) : 1 No
2. Electrical Hot Plate - 1/1.5 KW : 1 No
3. Burette Stand : 4 No
4. Pipette Stand : 1 No
5. Funnel Stand : 1 No

B) GLASS WARES:

1	Pipette with Safety Bulb-Glass	5 ml 10 ml	2 Nos 1 No
2	Measuring Cylinder -Glass	25 ml 50 ml	1 No 2 Nos
3	Standard Flask -Glass	100 ml 250 ml 500 ml	1 No 1 No 1 No
4	Conical Flask -Glass	250 ml	1 No
5	Burette -Glass	25 ml	1 No
6	Glass Rod ( with Police man)	---	3 Nos
7	Reagent Bottles ( Glass or PP) Amber Coloured -Glass	500 ml 500 ml	10 Nos 4 Nos
8	Funnel - Glass	2” 3”	4 Nos 3 Nos
9	Beaker -Glass	250 ml	1 No

C) OTHERS:

1. Spatula ( Ni plated or S.S.) : 1 No
2. Camel Hair Brush : 1 No
3. Watch Glass – 3 Inch Dia : 1 No
4. Black Ceramic Tile – Glazed : 1 No
5. What Man No: 41 Filter Paper : 1 Packet
6. Wash Bottle ( Polypropylene 500 ml) : 1 No
7. Pestle & Mortar : 1 No

D) CHEMICAL REQUIREMENTS:

1. S.NO	ITEM	QUANTITY
   1	Ammonia Solution 25% LR Grade	1 x 500 ml
   2	Silver Nitrate L.R Grade	1 x 25 Grams
   3	Potassium Iodine L.R.Grade	1 x 250 Grams
   4	Acetic Acid Glacial L.R.Grade	1 X 500 ml
   5	Nitric Acid 70% L.R.Grade	1 x 500 ml
   6	Ferric Sulphate G.R.Grade	1 x 500 Grams
   7	Potassium Thlo Cyanate G.R.Grade	1 x 500 Grams
   8	Lead Carbonate L.R.Grade	1 x 500 Grams
   9	Mercury ( II ) Chloride L.R.Grade	1 x 250 Grams
   10	Phenolphalein Indicator Solution	1 x 500 ml
   11	0.1 N Hydrochloric Acid Solution	1 x 125 ml
   12	Distilled water ( Analytical Grade )	30 ltr
   13	Std. Sodium Thlo Sulphate Solution	1 Packet
   14	Hydrochloric Acid l.R.Grade	1 x 500 ml
   15	Std. Iodine Solution	1 Packet
   16	Starch Soluble L.R grade	1 x 250 Grams
   17	Mercuric Iodine L.R.Grade	1 x 100 Grams

PREPARATION OF REAGENTS:

1. N/100 Silver Nitrate Solution.

a) Weigh Exactly 0.425 gm of Silver Nitrate.

b) Carefully transfer to a 250 ml Std Flask and make up to the mark.

b) Carefully transfer to a 250 ml Std Flask and make up to the mark.

Note:

: 1) Silver Nitrate is deliquescent and hence the crystals after weighing Should be stored air tight.

2) All the glass apparatus should be rinsed well before use.

2. 10% Potassium Iodide Solution -100 ml.

Weigh about 10 gms of Potassium Iodide and dissolve in about 100 ml of water.

3. 10% Silver Nitrate Solution.

Weigh about 10 gms of Silver Nitrate and dissolve in 100 ml of distilled water.

4. 4% V/V Acetic Acid Solution -500 ml.

Transfer about 20 ml of Glacial Acetic Acid in to 500 ml std.Flask and make up to the mark.

5. 2% V/V Acetic Acid -500 ml.

Transfer about 10 ml of Glacial Acetic Acid 70% in to 500 ml std.Flask and make up to the mark.

6.10% V/V Nitric Acid -500 ml.

Transfer about 55 ml of Nitric Acid 70% in to 500 ml std.Flask and make up to the mark.

7.Ferric Reagent -500 ml.

Transfer about 50 gms of Ferric sulphate in to a 500 ml Beaker and add about 300 ml water And boil for few minutes. Cool and filter, if necessary. Make up the above to 500 ml.

8. N/10 Potassium Thio Cyanate solution-500 ml.

Weigh exactly 5gm of Potassium Thio Cyanate and transfer carefully in to a 500 ml std flask And make up to the mark. Standardise with N/100 Silver Nitrate Solution.

9. Mercuric Reagent -500 ml.

a) Transfer about 90gms of Potassium Iodide in to a 500 ml beaker and dissolve it in about 50 ml of water.

b) Transfer about 30gms of Mercuric Chloride in to a 250 ml beaker and add about 100 ml of water and heat it slightly ( Do not Boil ) to dissolve it.

c) Add B to A.

d) Make up to 500 ml.

10. Starch Indicator Solution

Triturate 2.5 gms of starch 0.01g. of Mercuric Iodide with 30 ml of cold water and slowly Pour it with stirring into 500 ml of boiling water Boil for three minutes. Allow to cool and Settle.

BATH ANALYSIS

STOCK / SAMPLE SOLUTION:

1. Dip a clean, polished stainless steel metal rod in the molten bath, collect the sample and grind.
2. Weigh exactly 5 gm and dissolve in about 50 ml of water in a 100 ml std Flask.
3. Add about 1 gm of lead carbonate, mix and make up to the mark.
4. Shake well, settle for 5 minites and filter.
5. Discard the precipitate and use the Filtrate for further analysis.

1. CYANIDE :

PRINCIPLE : Cyanide is estimated by titrating with Silver Nitrate in the presence of Potassium Iodide.

APPARATUS:

1. 10 ML Pipette ( with safety Bulb & Suction)
2. 250 ml Conical Flask.
3. 25 ml Burette

REAGENTS :

1. Ammonia Solution ( 25% LR Grade)
2. 10% Potassium Iodide Solution.
3. N/100 Silver Nitrate Solution.

PROCEDURE :

1. Pipette our 10 ml of the sample solution in to the conical flask.
2. Add about 30 ml of Ammonia Solution.
3. Add about 50 ml if Distilled water.
4. Add 1 ml of Pottassium Iodide solution.
5. Titrate with Silver Nitrate Solution until a faint but permanent.
6. Cloudiness appears

RESULT : % of Cyanide = ml of Silver Nitrate x 0.103

Note:

1. Black Title background should be used for detecting the sharp end point.
2. All glass wares should be thoroughly rinsed with distilled water.
3. Only good quality distilled water should be employed

2. CYANATE:

PRINCIPLE: Cyanate is converted in to Silver Cyanate and then to Silver Acetate. The Silver Acetate is dissolved to form Silver Nitrate, Which is titrated against Potassium Thio Cyanate with Ferric Indicator.

APPARATUS:

1. 5 ml Pipette ( with safety Bulb suction ) : 1 No
2. 50 ml Measuring Cylinder : 2 No
3. cFunnel & Whatman Filter No: 41 paper : 1 No each.
4. 250 ml Beaker : 1 No
5. 500 ml Beaker : 1 No

REAGENTS:

• 10% Silver Nitrate Solution.

  4% V/V Acetic Acid Solution.

  2% V/V Acetic Acid Solution.

  10% V/V Nitric Acid Solution.

  Ferric Reagent 

  N/10 Potassium Thio Cyanate Solution.

PROCEDURES:

1.  Pipette out 5 ml of the sample solution in to 250 ml beaker.
2.  Add 10 ml of 10% Silver Nitrate Solution.
3. Mix well and add 50 ml of 4% Acetic acid solution.
4. Filter and wash two or three times with 2% Acetic Acid Solution.
5. Reject the filtrate and transfer the filter paper in to 500 ml beaker.
6.  Add 100 ml of 10% Nitric Acid solution. Shake well and wait for 5 minutes.
7.  Add 5 ml of Ferric Reagent.
8. h) Titrate with N/10 Potassium Thio Cyanate Solution to a brick red colour.

RESULT: % of Cyanate = ml of Potassium Thio Cyanate x 1.60

3. CARBONATE:

PRINCIPLE: Carbonate is titrated with Hydrochloric Acid with Phenolphthalin As indicator in the presence of Mercuric Reagent.

APPARATUS:

1.  250 ml Conical Flask : 1 No
2.  25 ml Measuring Cylinder : 1No
3.  50 ml Measuring Cylinder : 1 No
4.  25 ml Burette : 1 No

REAGENTS:

Mercuric Reagent.
Phenolphthalin Indicator Solution.
N/10 Hydrochloric Acid Solution.

PROCEDURE :

a) Weigh accurately 250 mg of the sample.
b) Add about 50 ml of Distilled water.
c) Add about 25 ml of the Mercuric reagent.
d) Add 4-5 drops of Phenolphthalin Indicator.
e) Titrate with N/10 Hydrochloric Acid solution until the colour changes from pink to yellow.

RESULT: % of Carbonate = ml of Hydrochloric Acid x 2.4

BATH CORRECTION:

To decrease the Carbonate by 1%, Add 1.2 Kgs of Frank Nirogen for every 100 kgs of the bath.

4. SULPHIDE:

PRINCIPLE: Sulphide is reacted with excess of Iodine and back titrated with std. Sodium Thio Sulphate in the presence of starch Indicator.

APPARATUS:

1. 10 ml Pipette ( with safety bulb & suction) : 1 No
2. 250 ml Conical Flask : 1 No
3. 25 ml Measuring Cylinder : 1 No
4. 25 ml Burette : 1 No

REAGENTS:

Starch Indicator

Conc. Hydrochloric Acid

N/1000 std Iodine Solution

N/1000 std Sodium Thio Sulphate Solution

PROCEDURE:

a) Weigh accurately 5 gms of the bath sample.
b) Add 100 ml of water and dissolve.
c) Add 10 ml of std. N/1000 Iodine Solution.
d) Add 10 ml of Conc. Hydrochloric Acid.
e) Add few drops of Starch Indicator.
f) Titrate the excess Iodine with std. Sodium Thio Sulphate Solution.

RESULT : Sulphide in ppm = ml of Iodine consumed x 3

REPLENISHMENT:

To raise the sulphide content by 1 ppm. Add 0.5 gms of K ₂ S, for every 100 Kgs of the bath.

SL.NO	TROUBLE	POSSIBLE REASONS	CORRECTIVE ACTION
1	Lower hardness	1. Lower Cyanate Content 2. Lower Temperature 3. Shorter treatment time. 4. Material mix-up	Add required Nirogen Check Thermocouple. Increase the treatment time. Check the Components. Add required Nirogen. Add required K₂S.
2	Thin Surface Layer	1. Low Cyanate Content. 2. Low slpjide content. 3. Low Temperature 4. Low Air Flow	Check Thermocouple. Check flow meter, Ring for any Obstruction / break.
3	Loose black coating	1. High Sulphide content. 2. High Temperature 3. Low Air Flow	Check Floe Meter, Ring for any Obstruction / break. Check Thermocouple. Check Flow meter, Ring for any Obstruction / break. Reduce the Load.
4	Spot finishes	1. High Temperature 2. Non uniform Air Flow. 3. Charge too big for the pot Capacity.	Adjust with air flow. Pre Heat At 400° C to 90 minutes. If possible carry out sand blasting.
5	Orange peel or Exfoliation type	1. Sulphide content more. 2. Ommision of Pre heating. 3. Surface superficially work Hardened such as grinding Or polishing.

FRANK ENDUROX

INTRODUCTION:

FRANK ENDUROX is a blackening salt which produces attractive, corrosion resistant Black oxide finish after EPSILON Treatment.

ADVANTAGES:

Being a chemical conversion coating, the coating is integral with the metallic surface and posses fairly good resistance to corrosing and abrasion. Another added advantages is the simplicity of the process which does not require any chemical knowledge / control.

PROCESS:

HEATING : By Electrical

TEMPERATURE : 360 - 450°C ( Depending on the material)

TREATMENT TIME : 20-40 Minutes.

POT MATERIAL : EN 304 / 310

HANDLING PRECAUTIONS:

FRANK ENDUROX contains strong alkalies, which may cause severe skin burns on prolonged exposure. Operators should wear necessary gloves, goggles, aprons and gum boots.

In case of accidental splash on eyes, wash several times with liberal quantities of water and seek medical attention, if irritation persists.

STORAGE:

The material should be kept air tight, as exposure to extreme humidity and atmosphere will reduce the power of the salt.