Sandvik Bioline 1RK91 is a precipitation hardening stainless steel specifically designed for applications
requiring high strength combined with good ductility in the final product and high formability in the as-delivered condition. The strength is increased after ageing of the final product.
The characteristics in general can be said to be a combination of properties of ordinary austenitic
stainless and low alloyed ferritic steels. For example, elastic modulus, mechanical properties and thermal expansion are comparable to ferritic steels (such as low alloyed carbon steels or chromium steels) while corrosion resistance is more comparable to austenitic
stainless steels.
-
Excellent mechanical properties; very high tensile
strength and hardness levels can be achieved
-
Corrosion resistance comparable to ASTM 304L or ASTM
316L depending on condition
-
Retained mechanical properties at temperatures up
to at least 400°C (750°F)
-
Very good relaxation properties
-
Good weldability
Standards
Product standards
Chemical composition (nominal) %
|
C |
Si |
Mn |
P |
S |
Cr |
Ni |
Mo |
Cu |
Ti |
Al |
| ≤0.02 |
≤0.5 |
≤0.5 |
≤0.020 |
≤0.005 |
12 |
9 |
4 |
2.0 |
0.9 |
0.4 |
Forms of supply
The following range of strip thicknesses and widths
can be supplied as standard. Other dimensions can be offered on request.
|
Thickness |
Width |
Thickness |
Width |
|
mm |
mm |
in. |
in. |
| 0.015 - 4.00* |
2 - 330 |
0.0006 - 0.158 |
0.079 - 13 |
* Depending on requested tensile strength.
The cold-rolled strip can be supplied in coils,
bundles, on spools or in cut lengths.
Sandvik Bioline 1RK91 can also be delivered as
wire/bar.
Mechanical properties
The possible ranges for the mechanical properties
both in the cold-rolled and aged condition are indicated below.
The strength level after ageing depends on the amount
of cold deformation and therefore also on the final dimension.
At 20°C (68°F)
|
Condition |
Tensile strength, Rm |
Proof strength, Rp0.2a) |
|
|
MPa |
ksi |
MPa |
ksi |
| Bar |
Cold worked |
- |
- |
1100 |
159 |
|
Aged |
1000-2100 |
145-304 |
900-1800 |
130-261 |
| Flat
rolled wire |
Cold worked
Aged |
950-1850
1400-2500 |
138-268
203-363 |
600 - 1800
1200
- 2400 |
87 - 261
174
- 348 |
| Round
wire |
Cold worked
Aged |
950-2150
1400-3100 |
138-312
203-450 |
-
- |
-
- |
Strip
|
Annealed
Cold
rolled
Cold
rolled + aged |
max 750
950-1850
1400-2600 |
max 109
138-268
203-377 |
max 350
600-1800
1200-2500 |
max 51
87-261
174-363 |
1 MPa = 1 N/mm2
a)
Rp0.2
correspond to 0.2% offset yield strength.
Examples of strength values for the heat treated
(aged) condition are shown below. As the true values depend on product form and production route, the exact value for a specific product or application must be determined in each case. Please contact Sandvik for further information.
At elevated temperatures
The values represent testing on material cold worked
to a tensile strength of 1650 MPa and subsequently aged at 475°C to 530°C for 4 hours.
|
Temperature |
Tensile strength Rm
, MPa |
|
°C |
20 |
100 |
200 |
300 |
400 |
Bar form
Wire
and strip form |
2000
2450 |
1900
2400 |
1770
2200 |
1630
2125 |
1510
1975 |
Physical properties
The physical properties of a steel are related to
a number of factors, including alloying elements, heat treatment and manufacturing process. The data presented below can generally be used for rough calculations.
Density:
7.9 g/cm3,
0.29 lb/in3
Resistivity:
cold worked: 0.97 μΩm, aged: 0.83 μΩm
Thermal conductivity
1)
|
Temperature, °C |
W/m °C |
Temperature, °F |
Btu/ft h°F |
| 20 |
14 |
68 |
8 |
| 100 |
16 |
200 |
9 |
| 200 |
18 |
400 |
10.5 |
| 300 |
20 |
600 |
11.5 |
| 400 |
21 |
700 |
12 |
1) For material in heat treated (aged) condition
Specific heat capacity
1)
|
Temperature °C |
J/kg °C |
Temperature °F |
Btu/ft h°F |
| 20 |
455 |
68 |
0.11 |
| 100 |
490 |
200 |
0.12 |
| 200 |
525 |
400 |
0.13 |
| 300 |
560 |
600 |
0.14 |
| 400 |
600 |
700 |
0.14 |
1) For material in heat treated (aged) condition
Thermal expansion
Average values in temperature ranges. The steel
grade has a coefficient of thermal expansion close to that of carbon steel. This gives it definite design advantages over normal austenitic stainless steels.
Metric units
1)
|
Grade |
Temperature range, °C |
|
30-100 |
30-200 |
30-300 |
30-400 |
| Cold worked |
11.5 |
11.5 |
11.5 |
11.5 |
| Aged |
11.5 |
12 |
12 |
12.5 |
| For comparison: |
| Carbon steel (0.2%C) |
12.5 |
13 |
13.5 |
14 |
| ASTM 304L |
16.5 |
17.5 |
18 |
18 |
1) (x10-6/°C)
Imperial units
1)
|
Grade |
Temperature range, °F |
|
86-200 |
86-400 |
86-600 |
86-700 |
| Cold worked |
6.5 |
6.5 |
6.5 |
6.5 |
| Aged |
6.5 |
6.5 |
7 |
7 |
| For comparison: |
| Carbon steel (0.2%C) |
7 |
7 |
7.5 |
7.5 |
| ASTM 304L |
9.5 |
9.5 |
10 |
10 |
1) (x10-6/°F)
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