|
US2992147A
|
|
Method of heat treatment using dual atmospheres
|
|
US2275106A
|
|
Circulation of heat treatment atmospheres
|
|
US2124573A
|
|
Enveloping atmosphere control
|
|
US2192191A
|
|
Heat treatment atmosphere
|
|
US2101065A
|
|
Heat treatment furnace
|
|
US1851831A
|
|
Atmospheric control for heat treating furnaces
|
|
US1849714A
|
|
Heat treating furnace
|
|
US1808721A
|
|
Method for heat treatment
|
|
US1724583A
|
|
Electric furnace
|
|
US1429286A
|
|
Electric furnace
|
|
CA328982A
|
|
Heat treating furnace
|
|
CA459918A
|
|
Circulation of heat treatment atmospheres
|
|
CA400911A
|
|
Metal heat treatment atmosphere
|
|
CA236403A
|
|
Electric furnace
|
|
CA293930A
|
|
Electric furnace
|
|
CA392854A
|
|
Enveloping atmosphere controlling method
|
|
CA382405A
|
|
Heat treatment furnace
|
|
CA331035A
|
|
Electric furnace
|
|
CA671717A
|
|
Method of heat treatment using dual atmosphere apparatus
|
|
CA460535A
|
|
Heat treatment furnace
|
