where: k - constant rate dependent on temperature [1/s]; 
Q - activation energy [J /mol]; 
T - temperature [K] 
R - gas constant 8,31 [J/mol.K] 
A - constant dependent on frequency[1/s]. 
In order to determine “Q” and “A”, the natural logarithmic expression of eqn. (2) was used: 
1 
logk=-loge gL +log A 
8 8 RT 8 
The equation of the linear regression is: 
Y =-2.94819 - 145,39633; R*= 0,997 
Values of “Q” and “A” determined from the slope and intercept of the linear regression line are Q = 
2784 [J/mol] and A = 0,0011 [1/s] 
«net Phase Transformation in Surface Engineering 
From this material, 3 typical wear - test specimens ( ¢ 20 x 3 mm) was done.The abrasive wear test 
were performed by a mechanism with ball-on-plane contact (manganese steel ball was actuated by 
an electric motor) under 40 N load at room temperature for 1 h. 
reson fines are It was determinate the microhardness (HV o9; ) with an “Akashi MVK - E3” machine, in the 120 
um of the section of the wear specimens. An analysis of the microhardness’s test are presented in 
figure 2 and 3. 
weds oo sa, 
o \ ' T_=3000C | res CL 
aM oa mm rs T_=30000 | 
in arm 
% = 
= 5 
4 = 
ml recs ben SLT, 
on-Mehl-Avrami } 16 20 a0 40 50 60 70 88 90 100 110 120 as a mae va To 8 eo tee vi 1k 
a) Distance from the wear surface [um] b) Distance from the wear surface [um] 
ons interfacing 775 
750 x 
| T_=3000 C l 
is different in the re 
eases when the wo 
§ 
a 
tn aa u 
Th sw se 6 76 se sn wo to 1m 
Distance kom the wear surface [um] 
c) 
Fig. 2. The variation of the microhardness function of the distance from the wear surface, for Ti, = 
300° C and some isothermal times t;2 : a) Tiz = 5 min; b) Ti; = 30 min; ¢) Ti; = 60 min. 
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