Biomedical Engineering Reference
In-Depth Information
25
Ni-Cr
20
Austenite
15
10
Ferritic or
intermediate structure
5
0
0
5
10 15
Cr (w/o)
20
25
FIGURE 1.1
The effect of Ni and Cr contents on the austenitic phase of stainless steels containing 0.1% C. (Adapted
from Keating, F.H. 1956.
Chromium-Nickel Austenitic Steels
. London: Butterworths.)
TABLE 1.2
Mechanical Properties of 316L Stainless Steel for Implants
Ultimate Tensile
Strength, min. (MPa)
Yield Strength (0.2%
offset), min. (MPa)
Elongation 2 in.
(50.8 mm) min.%
Rockwell
Hardness
Condition
Annealed
485
172
40
95 HRB
Cold-worked
860
690
12
—
Source:
Adapted from ASTM. 1992.
Annual Book of ASTM Standards
,
Vol. 13,
Medical Devices and
Services
,
F139-F86, p. 61. Philadelphia, PA: ASTM.
1400
Ty pes 316L, 317L, 318
1200
Ultimate
strength
1000
0.2% Yield
strength
800
100
600
80
60
400
40
200
Elongation
20
0
0
0
20
40
Cold reduction (%)
60
80
FIGURE 1.2
Effect of cold work on the yield and ultimate tensile strength of 18-8 stainless steel. (Adapted from
ASTM. 1980.
Annual Book of ASTM Standards
. Philadelphia, PA: ASTM.)
