316LVM / 316LS
Material
316LVM, 316LS, UNS S31673, UNS S31675, W.Nr. 1.4441, 00Cr18Ni14Mo3, X2CrNiMo18-15-3
Overview
Stainless steel 316LVM, 316LS, S31673, S31675 for surgical implants.
The grade of 316LVM is a modified version of 316 with low carbon, high nickel and molybdenum. The purpose of the improvement of chemical composition is to maximize the corrosion resistance of the material by obtaining a ferrite free metallographic structure. In order to ensure purity and uniformity, the double vacuum smelting process (VIM+VAR) is generally adopted.
The material is non-magnetic even after strict cold – forming operation.
Characteristics
- ◎ High strength
- ◎ High fatigue strength
- ◎ Excellent microcleanliness
- ◎ Excellent structural homogeneity
- ◎ High surface finish
- ◎ Good biocompatibility
Application
316LVM material has been used for many years for permanent implants with good corrosion resistance under annealing conditions. Many new alloys have been studied with 316LVM as a reference. This stainless steel has good ductility in cold working condition.
316LVM is used for implant applications, suture line, orthopaedic connecting wire, skin suture nail, catheter, stylet, bone nail, hipstems, femoralheads, spinalsystems, acetabularcups, intramedullarynails, bonescrews, kneejoints, and pins, bone and nail plates, internal fixation devices, dental implants, staples.
This grade is also used for cardiovascular applications: guide wires, cardiac stents and for surgicalin struments and tools; blood lancets, stylets, trocars etc.
Chemical composition
| wt% | C | Si | Mn | P | S | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|---|
| ≥ | 17.00 | 13.00 | 2.25 | |||||
| ≤ | 0.03 | 0.75 | 2.00 | 0.025 | 0.010 | 19.00 | 15.00 | 3.00 |
| wt% | N | Cu | Al | Ti | Nb | Ca | Se |
|---|---|---|---|---|---|---|---|
| ≥ | |||||||
| ≤ | 0.10 | 0.20 | 0.010 | 0.020 | 0.050 | 0.020 | 0.020 |
Mechanical property (in annealed condition)
| Tensile Rm | 71 | ksi (min) |
|---|---|---|
| Tensile Rm | 490 | MPa (min) |
| R.p. 0.2% Yield | 27.5 | ksi (min) |
| R.p. 0.2% Yield | 190 | MPa (min) |
| Elongation (2″ or 4D gl) | 40 | % (min) |
Heat treatment and hardness
Solution treatment 1040°C (1900°F), water or other rapid cool.
Hardness: max. 192 HBW or 200 HV or 90 HRB
Micro cleanliness
The micro cleanliness of the steel as determined by Method A of Test Methods E 45, except using Plate I-r, on representative billet or tube samples from the heat shall not exceed the following
| Inclusion type | A | B | C | D |
|---|---|---|---|---|
| Thin | 0.5 | 0.5 | 0.5 | 0.5 |
| Heavy | 0.5 | 0.5 | 0.5 | 0.5 |
Available Process
- ◎ Cold worked
- ◎ Cold worked and bright annealed
- ◎ Cold worked, annealed and pickled
- ◎ Cold worked, polished (MP, EP etc.)
- ◎ Cold worked, bright annealed, polished
- ◎ (MP, EP etc.)
Common Tests
- ◎ Chemical composition
- ◎ Mechanical properties
- ◎ Hardness
- ◎ Grain size
- ◎ Intergranular corrosion
- ◎ Micro cleanliness
- ◎ Micro structure
- ◎ Eddy current
- ◎ Ultra sonic
- ◎ Hydrostatic
- ◎ Flare
- ◎ Flattening
- ◎ Surface condition
- ◎ Shape and dimension
- ◎ Positive Material Identification
Product forms
Capillary tube
OD 0.08 ~ 6.0 mm
WT 0.015 ~ 1.5 mm
Thin wall & Ultra thin wall seamless tube
OD 6.0 ~ 80.0 mm
WT 0.05 ~ 4.5 mm
Micro ID and heavy wall seamless tube
OD 3.0 ~ 50.0 mm
ID 0.30 ~ 5.0 mm
Precision seamless tube
OD 6.0 ~ 89 mm
WT 0.50 ~ 9.0 mm
Profiled seamless tube
Build to drawing
Build to specification
Precision conic seamless tube
Bigger end: OD3.0 – 28.0mm
Smaller end: OD2.5 – 25.0mm
WT: 0.25 – 1.50mm
HP / UHP BA+ tube
OD 1.0 ~ 76 mm
WT 0.10 ~ 10.0 mm
Service
- ◎ Precision cutting
- ◎ Tube surface treatment, like ID surface super mirror polishing, best level could reach Ra0.0015um
- ◎ Tube deep processing, like coiling, bending, end forming, body forming, laser processing, various needles processing, built to drawing and sample, etc.