HIGH TEMPERATURE CARBURIZING WITH CARBURIZING GAS PRODUCED IN THE CARBURIZING CHAMBER

Objectif

To save energy by carburizing bushings at 980 deg. C rather than the conventional 920-930 deg. C and recovering the heat for the subsequent quench hardening, thereby saving the need to construct gas generators and to consume methane as fuel.
The total energy recovery is about 60% compared to the standard carburizing method.
The main factors which contribute to obtain this result are:
1) Recovery of the furnace itself, owing to the introduction of exchangers;
-more accurate combustion
-better insulation (air blanketing)
-lower holding times.
2) Generation of atmosphere inside the furnace, thus eliminating energy consumptions derived from the generation of inert or carburized atmospheres.
3) Computerized management, through microprocessor, of the whole system.
This continually grants the application of the most adequate parameters of the process for each kind of item to be treated, according to diagrams which have been already improved and stored in memory.
The main sections of the plant are the following ones.
1 - the zone for accumulation of components to be case hardened, which are arranged in baskets
2 - chamber for preheating up to 700-750 c
3 - case hardening chamber at a 980 c temperature, with formation of carburizing atmosphere in it
4 - chamber for cooling down to 850 c and keeping the bushings at this temperature, which is quench hardening temperature
5 - robot which withdraws bushings from this chamber and inserts them into the showers for quenching
6 - two - or three shower systems for quenching
7 - induction heating furnace to temper the edges of the bushings
8 - all stress relief furnace at a 200 c temperature
9 - automatic components discharge system.
The plant is completed by combustion and case hardening atmosphere formation, by process automation and control devices, by fume recycling and temperature maintaining in the furnace equipment.
The program forecasts a prototype to be constructed and tested, to which a complete realization of the plant which will involve 7 to 8 furnaces more, will follow.
The tests on the prototype will be performed partially in a laboratory and partially in shops managed by ITM, partly by customers of ITM for endurance tests and for checking energy saving. Foreseen tests are:
1 - preliminary case hardening tests at different temperatures up to 980 c in a pit furnace with conventional atmosphere and determination of mechanical and structural characteristics of the case hardened layer after quench hardening by the conventional method
2 - tests of direct quench hardening after high temperature case hardening with the same determinations mentioned in the point 1
3 - case hardening tests with atmosphere produced in case hardening chamber, at different temperatures and direct quench hardening in a furnace with small size chambers, with the same determinations mentioned in the point 1
4 - preliminary tests of case hardening at 980 c with atmosphere produced in case hardening chamber in a properly modified pit furnace, with the same determinations mentioned in the point 1.

Programme(s)

ENG-ENALT 1C - Programme (EEC) of financial support for projects to exploit alternative energy sources, 1979-1984

Thème(s)

1.6 - INDUSTRY

Appel à propositions

Data not available

Régime de financement

DEM - Demonstration contracts

Coordinateur

Italtractor Itm SpA

Contribution de l’UE

Aucune donnée

Adresse

Via per Modena 152
41014 Castel Vetro Potenza
Italie

Coût total