In this issue, the effect of gas heat treatment ambient at the temperature of 950C
for 8hours using the gases NH3 or CH4 and using the gases NH3 and CH4 for
(4+4)hours of the distribution of the doping elements on Titanium alloys BT9 was
studied.
Oxide formation at the different treatment ambient as a reason of gas-phase
oxygen distribution to high depths in the samples was discovered.
We have studied in this paper the effect of thermal gaseous using NH3 – gas at some
diffusion layers properties of tool steel 20 in temperature range (550 ,650 ,750, 850) 0C ,
4h at each one . The purpose of this heat treatment is to get and determ
ine the microhardness,
fatigue and corrosion resistance.
The micro-hardness was determined using Vickers's tester with values ranged
between ( 130-435 ) HV.
In order to verify these results, we studied the microstructure if the surface layers
using metallurgical microscope and SEM (Scanning Electron Microscope). Furthermore
the corrosion resistance was studied after immersing it in sea water for two year.
