General description
BPS-SB-1500SM is a precipitation hardenable, austenitic stainless steel of the 17Cr-7NiPH type, with a high tempering effect and good structural stability. This makes it a suitable choice for complex, It is also suitable for use at elevated temperatures.
BPS-SB-1500SM is characterized by:
• high tempering effect
• low relaxation at high stresses and elevated temperatures
• higher fatigue strength
• very small distortion during tempering
• high service temperatures Chemical composition (nominal) %
| C |
Si |
Mn |
P max |
S max |
Cr |
Ni |
Mo |
Others |
| 0.08 |
0.5 |
0.9 |
0.030 |
0.015 |
16.5 |
7.5 |
- |
Al=1.0 |
Forms of supply
BPS-SB-1500SM is supplied, as standard, in the cold rolled condition. Steel belt steel can be supplied in coils, bundles, on plastic spools or in lengths. The edges can be either slit or smoothly rounded.
Dimensions
The following range of thicknesses and widths can be supplied as standard.
| Thickness, mm |
Width, mm |
Thickness, inch |
Width, inch |
| 0.6 - 3.00* |
2 -2400 |
.0006 - .118 |
.079 - 100 |
Mechanical properties
Static strength
Nominal values at 20°C (68°F)
| Condition |
Tensile strength, |
Rm |
Proof strength, Rp0,2a) |
Elongation, A11,3 |
 |
MPa |
ksi |
MPa |
ksi |
% |
| C |
1300 |
190 |
1150 |
165 |
12 |
| CT |
1550 |
225 |
1400 |
203 |
6 |
a) Rp0.2 corresponds to 0.2% offset yield strength.
1 MPa = 1 N/mm2
C = Cold rolled
CT = Cold rolled and tempered, 480°C (896°F)/1 h
Fatigue strength
Nominal values at 20°C (68°F) in a normal dry atmophere. The fatigue limit is defined as the stress at which 50% of the specimens withstand a minimum of 2 million load cycles.
Reversed bending stress
Average stress = 0
Bending transversal to rolling direction.
Comparision made for different ticknesses and tensile strength levels.
Tensile strength,
Rm |
Fatigue limit, MPa |
Tensile strength,
Rm |
Fatigue limit, ksi |
|
Thickness, mm |
|
Thickness, inch |
|
MPa |
0,50 |
0,75 |
ksi |
0.020 |
0.030 |
|
1300 |
|
± 405 |
189 |
|
± 58.8 |
|
1500 |
± 555 |
|
218 |
± 80.5 |
| Fluctuating tensile stress
Minimum stress = 0
Specimens parallel to rolling direction.
Different thicknesses and tensile strength levels.
Tensile
strength,
Rm |
Fatigue limit,
MPa |
Tensile strength,
Rm |
Fatigue limit, ksi |
 |
Thickness, mm |
|
Thickness, inch |
| MPa |
0,50 |
0,75 |
ksi |
0.020 |
0.030 |
| 1300 |
|
340 ± 340 |
189 |
|
49.3 ± 49.3 |
| 1500 |
390 ± 390 |
360 ± 360 |
218 |
56.6 ± 56.6 |
52.2 ± 52.2 | Physical properties
The physical properties of a steel relate to a number of factors, including alloying elements, heat treatment and manufacturing route, but the following data can generally be used for rough calculations. These values refer to cold rolled material, at a temperature of 20oC(68oF) unless otherwise stated.
Density 7.9 g/cm3 (0.29 lb/in3)
Resistivity 0.9 mWm (35.5 mWinch)
Modulus of elasticity
as delivered´ .......................................... approx 180 000 MPa (26 100 ksi)
tempered ............................................... approx 190 000 MPa (27 550 ksi)
Shear modulus
as delivered ......................................... approx 70 000 MPa (10 150 ksi)
Specific heat capacity 500J/kg°C (in the temperature range 50-100°C)
Thermal expansion mean values in temperature ranges (x10-6)
| Temperature, °C |
per °C |
Temperature, °F |
per °F |
| from 20 - 100 |
13 |
from 68 - 200 |
7 | Thermal conductivity
|
Temperature, °C |
W/m °C |
Temperature, °F |
Btu/ft h °F |
| 20 |
15 |
68 |
8.5 |
| 100 |
15 |
210 |
8.5 |
| 300 |
19 |
570 |
11 | Corrosion resistance
It is very important to avoid corrosion in spring applications so as not to impair spring properties. BPS-SB-1500SM is an Marstenitic stainless steel and has sufficient corrosion resistance in most spring applications.
Heat treatment
BPS-SB-1500SM is a precipitation harden able steel and, compared to standard austenitic stainless spring steels e.g. type AISI 301, has a more pronounced tempering (ageing) effect. Consequently, it can be supplied with a comparatively low tensile strength in order to provide good forming properties, but still reach a high tensile strength after forming, by a simple heat treatment. Tempering also improves fatigue and relaxation resistance and, furthermore, it will decrease the internal stresses present in the spring after forming.
Welding
BPS-SB-1500SM like most austenitic stainless steels, has good weld ability. Welding, however, introduces excess heat into the material closest to the weld that breaks down the structure formed by cold working. As a consequence, this will decrease the mechanical properties of the welded area. The lowest practical heat input, <1,0 kJ/mm, and inter pass temperature for multi pass welding, <100°C, is recommended.
In most cases, the TIG(GTAW) method is preferable. It can be used either autogenously (without filler metal) or with filler metal. In both cases, pure argon (99,99%) should be used as a shielding gas.
When filler metal is used, 19.9.L or 19.9.LSi is recommended. Note that the weld metal will not be able to precipitation harden in this case.
Disclaimer
Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice.
This data sheet is only valid for material. Other material, covering the same international specifications, does not necessarily comply with the mechanical and corrosion properties presented in this datasheet. |
