Presentation of the hot-dip galvanising process and of the different parameters that are important when choosing one product over another. There are two suggestions for different types of treatment lines: a fully acid line with enhanced protection for rough environments needing passivation and another line with alkaline degreasing for extremely greasy parts.

1. SOCOVRAI®
Ptg. de la Masìa, 13 bxos LD6
08349 Cabrera de Mar – Barcelona (España)
Tel: +34 93 754 17 47– Fax: +34 93 754 16 52
admin@angem.com

2. Protect steel & iron against
corrosion
Hot-dip galvanizing
• A Zn layer is chemically attached to the steel
surface.
• Zn corrodes slower than iron and, thus, protects
iron from corroding.
• Very strong protection against corrosion.
Electroplating
• Different metals (Ni, Cr…) are attached to the
base metal surface.
• Used for high-gloss applications.

3. HDG is used in heavy-duty
industries
Building & Construction
Street Furniture & Road Safety
Wire frame
Utilities & Piping
Agricultural-used steel
Transportation & Automotive
Fasteners

4. Hot-dip galvanising stages
Degreasing
Etching
Flux
Galvanising
• Acid (cold, pre-etching)
• Alkaly (warmed, needs
rinsing off)
Rinsing
• Mechanic
• Water-based dilution: acid or alkaly
• ZnCl2 and NH4Cl double
and triple salts
• ZnCl2
Rinsing
• Protection against corrosion
Drying
Passivation
• Protection against white corrosion

5. Our
products

6. ANGEM proposes the full range of
products
DEGREASING
ETCHING
FLUX
GALVANISING
PS series
PASSIVATION
IC series
Additives
Salts
Additives
Additives
Passivants

7. Degreasers
Acid
Alkaly
SOCOVRAI®
PSAG
SOCOVRAI®
PSB
SOCOVRAI®
PSJ
SOCOVRAI®
PSMM
SOCOVRAI®
PS9M
SOCOVRAI®
PS198S
SOCOVRAI®
PS3xE
(electrolithic)

8. How to choose a degreaser
Shape and
quanity of
parts
Dirt type
Process
cost
Alloy type
Degre
aser
Form of
application

9. Advantages of acid degreaser
Acie
Alkaly

10. Etching
Corrosion
inhibitor
Additives
SOCOVRAI®
IC111
SOCOVRAI®
AF132
SOCOVRAI®
IC115
SOCOVRAI®
AH131N
SOCOVRAI®
IC33
SOCOVRAI®
IC120

11. A corrosion inhibitor improves
etching
Reduce Fe
concentration
Avoid overetching

12. Optimum etching requires a
balance between HCl y Fe
Difficult to control the acid attack on the metal
• Higher temperature
• Higher HCl
concentration
Etching
speed
• Higher Fe
concentration
Reduce bath activity

13. A CI enlarges the margin of
etching
Decapado óptimo en HCl a 20ºC
Conc. de Hierro / (g/L)
300
250
Exhausted bath
200
Renovate bath
150
HCl attacks base
A corrosion inhibitor enlarges margins
metal
100
50
0
0
50
100
150
200
Conc. HCl / (g/L)
Tiempos mayores
Óptima
Saturación
250

14. SOCOVRAI ® IC120:
environmentally friendly
No
VOCs
Low
toxicity
No
APEs
No
ADR
SOCOVRAI®
IC 120
Environmentallyfriendly
Has alcoxylated alcohol and phosphonated
derivatives

15. SOCOVRAI® AH131N reduces
process vapor
Socovrai
AH131N
Etching with HCl + AH131N

16. Flux
Salts
Additives
ZnCl2
SOCOVRAI®
AF132
Double salt
SOCOVRAI®
ATH3
Triple salt

17. Galvanizing
Additives
SOCOVRAI®
AR32

18. Passivation
Without
Chrome(VI)
With
Chrome(VI)
Passivation
Tri
ADL 3P
Passivation
22A

19. Our
suggestions

20. High-protection acid line
DEGREASING
ETCHING
FLUX
GALVANIZING
PASSIVATION
SOCOVRAI®
PSAG
80 – 130 g/l
25ºC
Yearly
cleaning
SOCOVRAI®
IC120 (0,3%)
+ AH131N (2
l/m3)
HCl] >100 g/L,
[Fe3+]<140 g/L
T: 25 ºC
DE-ZINC
SOCOVRAI®
IC 33
Sel double +
SOCOVRAI®
AF132 (5 g/l) +
ATH3 (0,5%)
D: 1,2 – 1,26 g/l
65 -70ºC
SOCOVRAI®
AR32
ADL 3P
450ºC
50-70ºC

21. Line with alkaly degreaser
DEGREASING
RINSING
ETCHING
FLUX
GALVANIZING
SOCOVRAI®
PSB
7 -20 %
55 - 60ºC
Cleaning
every 6
moths
SOCOVRAI®
IC120 (0,3%)
+ AH131N (2
l/m3)
HCl] >100 g/L,
[Fe3+]<140 g/L
T: 25 ºC
DE-ZINC
SOCOVRAI®
IC 33
Sel double +
SOCOVRAI®
AF132 (5 g/l) +
ATH3 (0,5%)
D: 1,2 – 1,26 g/l
65 -70ºC
SOCOVRAI®
AR32
450ºC

22. ANGEM Specialities is:
Technology
Product
Proximity
Technical
support
Specialized in
metal
Speed
Bath analysis
R+D
Customized
products
Competitive
prices
Agility
ISO 9001
Ley de envases
–R.D.782/1998