3rd_ET_WP2_PROGRESS MEETING
Important points discussed in the meeting are listed below:
Pre-prototypes manufacturing:
- 314L: Small flanges under machining. It is expected that the installation starts around the 20th of March;
- S315MC: Flanges welding pending. Radiographic inspection on-going in qualification plate;
- AISI 430:
- Welding studies confirmed a significant grain growth and ductility reduction inducing a brittle fracture during tensile testing
- Phase identification and quantification is on-going
- Hardness value for AISI430 according to ASTM A240M* should be ≤ 183 HBW
- Next test in autogenous mode will be done looking for a weld width reduction
- Raw material from Notz metal (1 face grinded) is available in the Main Workshop. The purchase included 5 plates of 1x 1000 x 2000 mm: Purchase Requisition (DAI) 9513821 (cern.ch)
Test specimens:
- The vacuum test is progressing well and the preliminary studies to understand the thickness influence on the outgassing indicate that the rate is thickness independent;
- Nevertheless, additional testing is needed to better understand why machined samples present different behavior (plastic deformation...);
- Analyses on ULC from TataSteel will be presented to the company representatives on March 16th. FIB-SEM to be completed
Corrugated solution. Why?
Simulations performed indicate that the thin-walled corrugated solution is suitable for steels that can withstand external pressure with a thickness of around 1.3 mm (designed for a pipe diameter around 1.1 ma buckling differential pressure of 3 bars). Corrugation dimensions are for the moment stablished in 35 mm height and 120 mm pitch. (Information from Cedric and Hana).
Main advantages:
- No need of compensation bellows;
- Light structure that can be supported either from the roof or floor;
- Relatively easier to bake out;
- Reduced amount of material and therefore cost
Some of the challenges already highlighted:
- Circular welding
- Cleaning procedure
Cleaning test campaign. How to prepare representative samples?
- An study is bein prepared by Leonel in collaboration with an external company (Poligrat) to validate a degreasing procedure on pipes up to 15m long and 1.2 m diameter for the pilot sector;
- The goal of the study is to assess the initial surface contamination of the pipes and compare it with the results after degreasing;
- Up to now only the raw material pollution has been taken into account (oil protective layer and handling);
- In order to have a good reference for each material it is needed to understand possible contamination sources during forming and assembly
- In case it is needed, the extraction of test specimens can be postponed until the welding procedure for the pilot sector is defined. To be discussed
- CERN capabilities allow large diameters but the length is limited (numerous sections of 1 m would be needed). To be discussed.
Other:
- Manjunath will share ASAP an Excel table with the material available and samples inventory that everybody can update
- Erichsen test tooling procurement is under discussion in EN-MME-MM
*A240/A240M: 2022 / Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications