DIN 17 861
The DIN 17861 Standard provides the technical delivery conditions for the manufacture and supply of Seamless Circular Titanium and Titanium Alloy Tubes. This guides provides an overview to the key areas of the standard.
Overview
The standard covers titanium and titanium alloy bars making the distinction between CP Titanium and Low Alloy Titanium tubes used in chemical plant and industrial applications where the anti-corrosiveness of the metal is required against High Alloy Titanium tubes used primarily for the low mass and non magnetic properties and so used in advanced engineering, tooling etc. The standard does not cover the use of titanium tubes in aerospace applications, instead references the standard DIN 65 039. The standard only also cover circular tubing profiles. Finally the standard details a two class testing approach with the second class being a more comprehensive approach.Ordering Information
When ordering material under the DIN 17861 a formal specification approach is outlined with an essential or optional specification being used. A standard designation outlines the product definition and includes the following information:- The name of the product i.e. Titanium Tube
- The DIN Number production conforms to i.e. DIN 17 861
- Product Dimensions i.e. External Diameter, Wall Thickness, NPS Size, Length
- Titanium Grade as denoted by the designation name or number from the table 1 of the standard
- Supply condition symbol e.g. b
Essential Ordering Information
As per the DIN 17861 standard the standard way that titanium tubes should be specified includes the following:- Quantity of tubes (e.g. in meters of pcs)
- The name of the product i.e. Titanium Tube
- The DIN Number production conforms to i.e. DIN 17 861
- Product Dimensions i.e. External Diameter, Wall Thickness, Length from the table 5 of the standard
- Titanium Grade as denoted by the designation name or number from the table 1 of the standard
- Supply condition number
- Test class
- Inspection Document required
- For 3rd Party Inspections the Agency to use
Optional Ordering Information
As per the standard there a number of additional ordering requirements to be met:- Manufacturing Processes
- Chemical Composition
- Dimensions outside of those specified in the standard
- The proof strength differences at ambient temperatures
- Requirements for tightness testing
- Non-destructive testing requirements
- Testing observation requirements
- Continuous Markings
Titanium Requirements
The section covers the requirements for the manufacturing processes to be followed, the chemical composition to be achieved along with the mechanical properties, dimensions and tolerances, material conditions and tightness.Chemical Compositions
The chemical compositions to be achieved, referred to as the Ladle Analysis at each grade is by reference to the standards DIN 17 850 (Titanium) and DIN 17 851 (Titanium Alloys). The table below introduces the typical grade ranges.| Material | Chemical Composition (%) | |||||||
|---|---|---|---|---|---|---|---|---|
| Fe* max | O max | N max | C max | H** max | Others | Ti | ||
| Single max | Total Max | |||||||
| Ti1 | 0.15 | 0.12 | 0.05 | 0.06 | 0.013 | 0.10 | 0.40 | Remainder |
| Ti2 | 0.20 | 0.18 | 0.05 | 0.06 | 0.013 | 0.10 | 0.40 | |
** For the tubes less than 2mm in thickness the maximum hydrogen content is 0.015.
Mechanical Properties
The mechanical properties of the titanium tubes are required to meet the following mechanical properties at an ambient temperature with wall thickness’s to 12.5mm| Material | Minimum 0,2% proof strength*, Rp 0,2 in N/mm2 |
Minimum 1% proof strength*, Rp 1,0 in N/mm2 |
Tensile Strength, Rm, in N/mm2 |
Minimum elongation at fracture, A5, longitudinal, as a percentage |
|
|---|---|---|---|---|---|
| Designation | Number | ||||
| Ti1 | 3.7025 | 180 | 200 | 290 to 410 | 30 |
| Ti2 | 3.7035 | 250 | 270 | 390 to 540 | 22 |
| Ti3 | 3.7055 | 320 | 350 | 460 to 590 | 18 |
| Ti1Pd | 3.7225 | 180 | 200 | 290 to 410 | 30 |
| Ti2Pd | 3.7235 | 250 | 270 | 390 to 540 | 22 |
| Ti3Pd | 3.7255 | 320 | 350 | 460 to 590 | 18 |
| TiNi0,8Mo0,3 | 3.7105 | 345 | 370 | min 480 | 18 |
| TiAl6V4 | 3.7165 | 830 | Unspecified | min 900 | 10 |
| TiAl3V2,5 | 3.7195 | 520 | min 620 | 15** | |
| TiAl6V6Sn2 | 3.7175 | 930 | min 1000 | 8 | |
| * The 1% proof strength is required by default with the 0,2% proof strength required on specification ** For wall height of 1mm and below the A5 is 12% |
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| Material | Minimum 1% proof strength, Rp1,0 in N/mm2 at a temperature in C of |
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|---|---|---|---|---|---|---|---|
| Desgination | Number | 75 | 100 | 150 | 200 | 250 | 300 |
| Ti1 Ti1 Pd |
3.7025 3.7225 |
195 | 180 | 150 | 110 | 90 | – |
| Ti2 Ti2Pd |
3.7035 3.7235 |
255 | 235 | 195 | 145 | 115 | 105 |
| Ti3 Ti3Pd |
3.7055 3.7255 |
300 | 275 | 220 | 165 | 130 | 115 |
Dimensions and Tolerances
The DIN 17861 Standard defines a set of preferred dimensions with appropriate wall thicknesses for given Outside Diameters with specifications outside of the ranges to be subject ordering. The standard also defines an acceptable mass range is defined in terms of an equation and also against the list of preferred dimensions. For tolerances the following are to be followed:Outside Diameter and Wall Thickness Tolerances
The table below details out the permissible Outside Diameter and Wall Thickness Tolerances according the standard DIN 17 861.| Manufacturing Process |
Limit Deviation of Outside Diameter da |
Wall thickness, s | ||
|---|---|---|---|---|
| s:da ratio |
Limit Deviations | |||
| Over | Up to | |||
| Cold Formed | +/- 0,5% but at least +/- 0,1mm | – | – | +/- 10% but at least +/- 0,2mm |
| Hot Formed | +/-1 % but at least +/- 0,5mm | 0,100 | – | +/- 10% |
| 0,050 | 0,100 | +/- 12,5% | ||
| 0,025 | 0,050 | +/- 15% | ||
| – | 0,025 | +/- 20,0% | ||
Length Tolerances
The table below details out the permissible tube length tolerances according the standard DIN 17 861.| Type of Length | Outside Diameter | Length | Limit Deviations | ||
|---|---|---|---|---|---|
| Over | Up to | Over | Up to | ||
| As Manufactured Length | All Types | 2000 | 7000 | Not Specified | |
| Specified Length | All Types | Subject To Agreement | +/- 500 | ||
| – | 40 | – | 1000 | +1 0 |
|
| 1000 | 2000 | +2 0 |
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| 2000 | 3000 | +3 0 |
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| 3000 | 4000 | +4 0 |
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| 4000 | – | +5 0 |
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| 40 | 168 | – | 6000 | +5 0 |
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| 6000 | – | +10 0 |
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| 168 | – | – | – | +10 0 |
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Supply Preparation and Surface
The table below details out the differing processing and supply approaches according the standard DIN 17 861 which are to be state during ordering.| Conditions on Supply (symbol) |
Types of Treatment | Surface Appearance |
|---|---|---|
| a1 | Hot Formed, Not Heat Treated, Not Descaled | Oxidised |
| a3 | Hot Formed, Not Heat Treated, Descaled | Bright (Descaled) |
| b | Hot Formed, Heat Treated, Not Descaled | Oxidised |
| c1/c2 | Hot Formed, Heat Treated, Descaled (mechanically or my means of blasting and/or pickling) |
Bright |
| g | Cold Formed, heat treated in oxidic atmosphere | Bright (Heat Treated) |
| h | Cold Formed, heat treated in oxidic atmosphere, descaled (mechanically or by means of blasting and/or pickling) |
Bright (Descaled) |
| m | Cold formed, heat treated in inert gas or under vacuum | Bright (Descaled) |
| o | Polished externally | Bright (Polished) |
| Normal heat treatment parameters: electric/gas-fired furnace, oxidic atmosphere, inert gas or vacuum | ||
Testing Scope and inspection documents for the Test Classes 1 and 2
The different classes of testing and the respective testing to be carried out for each is outlined in the table below.| No | Test to be Carried out | As in Subclause |
Scope of Testing | DIN 50 049 Inspection Document* |
|
|---|---|---|---|---|---|
| Test Class 1 | Test Class 2 | ||||
| 1 | Ladle Analysis | 4.4.1 | 1 analysis per cast | Inspection Certificate B | |
| 2 | Product Analysis | 4.4.1 | 1 analysis per cast | ||
| 3 | Determination of H2 Content | 4.4.1 | 1 determination per cast or heat treatment batch |
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| 4 | Tensile Test at Ambient Temperature |
4.4.2 | 1 test piece taken from 1 test tube, per batch |
Inspection Certificate A, B or C or inspection report |
|
| 5 | Tensile Test at elevated Temperature |
4.4.3 | – | 1 test piece per cast and size |
|
| 6 | Flattening Test | 4.4.4 | 1 test piece taken from 1 test tube, per batch |
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| Drift or ring expanding test | 4.4.5 4.4.6 |
– | CF table 8 | ||
| 7 | Tightness test | 4.4.7 | All tubes | Inspection Certificate B | |
| 8 | Non-destructive test for laminations |
4.4.8 | – | All tubes where s is over 3,6mm |
Inspection Certificate B |
| 9 | Non-destructive test for longitudinal imperfections |
4.4.8 | – | All Tubes | |
| 10 | Non-destructive test for traverse imperfections |
4.4.8 | – | ||
| 11 | Visual Check | 4.4.9 | All tubes | Inspection certificate A,B or C or inspection report |
|
| 12 | Check for dimensional Accuracy | 4.4.10 | All tubes | ||
| * in accordance with DIN 50 049, the following parties are responsible for testing inspection certificate A: the inspector named in the official regulations inspection certificate B: the works inspector inspection certificate C: the purchaser’s authorised representative; inspection report: Both the purchaser’s authorised representative and the works inspector. |
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