1. IN AN ELECTRIC DISCHARGE HEAT-TREATMENT PROCESS WHEREIN A METAL WORK PIECE IS IMMERSED IN AN ELECTROLYTE AND AN ELECTRIC CURRENT IS PASSED THROUGH THE ELECTROLYTE WITH THE WORK PIECE AS ONE ELECTRODE, AT A SUFFICIENT VOLTAGE AND FOR A SUFFICIENT TIME PERIOD TO PRODUCE, IN THE LATTER STAGE OF SAID PROCESS, GASEOUS-ELECTRIC DISCHARGE HEATING THROUGH THE GASEOUS BLANKET GENERATED ELECTROLYTICALLY AND BY VOLATILIZATION AT THE WORK PIECE SURFACE IN THE INITIAL STAGES OF SAID PROCESS, AND THEREAFTER TERMINATING THE CURRENT FLOW AND ALLOWING THE WORK PIECE TO COOL IN THE ELECTROLYTE, THE STEP LOCALLY HEATING THE SURFACE LAYER OF THE ELECTROLYTE WHILE MAINTAINING THE UNDERLYING ELECTROLYTE AT A SUBSTANTIALLY LOWER TEMPERATURE, AND LOWERING THE WORK PIECE GRADUALLY INTO THE ELECTROLYTE THROUGH THE SURFACE LAYER THEREOF WHILE PASSING CURRENT THROUGH THE ELECTROLYTE WITH THE WORK PIECE AS AN ELECTRODE TO GENERATE A LAYER OF GAS AT THE ELECTRODE SURFACE WITHOUT HEATING THE ELECTRODE TO A TEMPERATURE HIGHER THAN THAT PRODUCED IN THE LATTER STAGE OF THE PROCESS.