Heat Treatment
HAYNES® 188 alloy is normally solution heat treated in the range of 2125-2175°F for a time to commensurate with section thickness. Annealing during fabrication can be performed at even lower temperatures, but a final, subsequent solution heat treatment is needed to produce optimum properties and structure.
Effect of Cold Reduction Upon Room-Temperature Properties*
Cold
Reduction
|
Subsequent Temperature
|
0.2%
Yield Strength
|
Ultimate
Tensile Strength
|
Elongation
|
Hardness
|
|
%
|
-
|
ksi
|
MPa
|
ksi
|
MPa
|
%
|
HR BW/C
|
|
0
|
NONE
|
66.9
|
460
|
137.2
|
945
|
54.2
|
98.1 HRBW |
|
10
|
105.9
|
730
|
151.5
|
1045
|
45.1
|
32.1 HRC |
|
20
|
132.9
|
915
|
165.9
|
1145
|
28.3
|
37.1 HRC |
|
30
|
167.0
|
1150
|
195.1
|
1345
|
13.4
|
41.2 HRC |
|
40
|
176.8
|
1220
|
214.9
|
1480
|
9.8
|
43.5 HRC |
|
10
|
1950°F (1065°C)
for 5 min.
|
91.2
|
630
|
148.5
|
1025
|
41.4
|
29.7 HRC |
|
20
|
87.8
|
605
|
153.3
|
1055
|
41.0
|
27.8 HRC |
|
30
|
84.2
|
580
|
158.3
|
1090
|
41.3
|
29.6 HRC |
|
40
|
90.8
|
625
|
162.7
|
1120
|
39.8
|
31.1 HRC |
|
10
|
2050°F (1120°C)
for 5 min.
|
64.7
|
445
|
143.0
|
985
|
50.1
|
21.9 HRC |
|
20
|
71.4
|
490
|
149.0
|
1025
|
47.2
|
24.5 HRC |
|
30
|
80.3
|
555
|
155.2
|
1070
|
43.7
|
27.6 HRC |
|
40
|
86.9
|
600
|
159.0
|
1095
|
43.2
|
29.5 HRC |
|
10
|
2150°F (1175°C)
for 5 min.
|
61.9
|
425
|
139.6
|
965
|
55.3
|
95.6 HRBW |
|
20
|
64.9
|
445
|
141.3
|
975
|
53.3
|
97.1 HRBW |
|
30
|
66.5
|
460
|
142.8
|
985
|
51.8
|
98.5 HRBW |
|
40
|
64.1
|
440
|
141.5
|
975
|
55.5
|
97.2 HRBW |
*Based upon rolling reduction taken upon 0.125 in. (3.2 mm) thick sheet. Duplicate tests.
HRC = Hardness Rockwell “C”.
HRBW= Hardness Rockwell "B", Tungsten Indentor.