Annealing And Hardening

annealing

Annealing salts are usually used in combination with an additive to prevent decarburization and oxidation of the treated components. The risk increases considerably as the treatment temperature rises. Depending on the mode of action, additives are divided into two groups.

The cyanide-free products bind successfully oxygen containing compounds and ensure the inert character of the melt. They can be used up to a temperature of 1100 °C.

The second class of additives gives the melt a certain carbon activity, which depends on both the concentration of the additive and the nature of the base salt. Due to the short treatment times the carbon activity is allowed to vary considerably from the carbon content of the steel and has not to be adjusted within close limits.

As an alternative to the classic GS products, the modern DUROFER® process for hardening being free of decarburization has proven itself in practice. (see Carburizing and Carbonitriding page 4)

annealing2annealing

 

Base Salt

Product

Application

Working
temp. in °C

GS 230

For tempering and quenching above 300 °C.

 

GS 430

For tempering, cooling or quenching of steel for which AS baths are not suitable.

500 – 700

GS 520

Replenishment salt for GS 430 baths.

 

GS 540

For heating and annealing.

600 – 950

GS 560

Barium free salt for annealing silver, gold and brass.

600 – 850

GS 660

Barium free salt for annealing steel and non-ferrous metals.

750 – 900

GS 670 For heating and annealing. 750 – 1000
GS 750 For heating and annealing. 850 – 1100

GS 960

For heating and annealing.

1050 – 1250

 

Additive salts for inert annealing; cyanide-free

Product

Application

R 2

For the prevention of decarburization and oxidation in combination with GS 540, GS 670 and GS 750

R 3

Barium-free additive for the prevention of decarburization and oxidation in combination with GS 670

 

Additive salts for preventing decarburization

Product

Application

 
C 1 For the prevention of decarburization and oxidation in combination with GS 540, GS 560, GS 660 and GS 670; is used, if the carbon content of the C 3 is undesirable

 

C 3 For the prevention of decarburization and oxidation in combination with GS 540, GS 560, GS 660 and GS 670; contains active carbon to form a bath cover  

 

For the prevention of decarburization and oxidation in combination with GS540, GS 560, GS660, GS 670, if the carbon content of C3 is undesirable.
C3:         For the prevention of decarburization and oxidation in combination with GS540, GS 560, GS660, GS 670. Contains active carbon to form a bath cover.