Stainless Steel Mass Research Articles

Inmetro’s participation in SIM kilogram dissemination project (SKDP) Mass stability analysis of the SIM21 mass standard (1 kg) over three years in the SIM Kilogram Dissemination Project (SKDP)

Inmetro’s mass laboratory (Lamas) participated in SIM Kilogram Dissemination Project (SKDP). The assessment of mass stability of the SIM21 1 kg stainless steel mass standard was carried out between 2018 and 2021. The results show a typical variability for a weighing system but not clear trend in measurements. Therefore one can say no mass drift for SIM21 mass standard was observed along this period.

Final report of APMP comparison of mass standards APMP.M.M-K5 (Sub-) multiples mass key comparison

Main textThis report describes a key comparison of mass standards APMP.M.M-K5, conducted between 19 participating members of the Asia-Pacific Metrology Programme (APMP). The APMP.M.M-K5 comparison was launched during the 13th meeting of the Technical Committee for Mass and Related Quantities APMP-TCM (2012).Two sets of stainless steel weights with five nominal mass values: 2 kg, 200 g, 50 g, 1 g, and 200 mg were used as travelling standards. These nominal values were chosen as they followed the nominal values of CCM.M-K5. The aim of the comparison is to verify the consistency of 2 kg, 200 g, 50 g, 1 g and 200 mg stainless steel mass standards among members of APMP-TCM.The program was piloted by the National Institute of Metrology, P.R. China (NIM). All the participants have provided their support and help to successfully organize and run the comparison. The nominated 19 participants have been divided into five petals and the corresponding five sets of transfer standards have been circulated within the groups simultaneously. The pilot laboratory measured the volumes and the magnetic properties of the standards before the circulation and had reported these values to the participants. The pilot laboratory has also verified the stability of all travelling standards for more than one year. The set of five weights was circulated among all the participating laboratories in August 2015 and received back from the last participant in August 2016. The final report of this comparison is being given in this document.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

UME Kibble balance operating in air

The UME KB-3 operating since 2020 allows the realization of kilogram under ambient air conditions owing to its distinguishing design and operation protocol. This is possible only because the coil pair is stationary but the surrounding magnet assembly is moving. The mechanically decoupled nature of the magnet assembly allows the implementation of a local vacuum for displacement measurements rather than a vacuum covering the entire apparatus. The balance operates in single mode with simultaneous operation of weighing and moving phases instead of successive phases. A novel dynamical measurement procedure is developed in order to conform with the single phase measurements. The paper describes the apparatus and presents the measurement results for stainless steel mass artefact with a nominal value of 1 kg. The mass of the artefact is measured with a total relative uncertainty of 54 ppb.

On mass dynamics in a closed ecological system, determined with a prototype vacuum mass comparator – a methodological validation study

Abstract The aim of this work was to validate a novel methodology for high-resolution, repetitive measurements of mass dynamics of biological processes and structures in a closed plant-earth ecosystem consisting of Mammillaria vetula and microorganisms. To perform these experiments, the living system was materially welded into a newly developed Titanium Weighing Hollow Body (TWHB) with a laser. Three non-vital, also hermetically welded and high-vacuum suitable, externally identical TWHBs, filled with sand, served as controls. All TWHBs were equipped with a feedthrough and integrated light source. LEDs generated continuous light in all four bodies, which drove the photobiological processes in the vital test body and allowed long-term growth. Mass differences of the TWHBs were measured with a vacuum mass comparator at four points in time three months apart against two stainless steel mass standards. The expanded measurement uncertainty of the mass increase of the vital TWHB was calculated according to the Guide to the Expression of Uncertainty in Measurement (GUM) in each of the three independent experiments. The mass gain of the vital over the three nonvital TWHBs over the total experimental period of 9 months was +18 μg with the expanded measurement uncertainty 30 μg. The resulting mass gain would have had to be > 48 μ g $ > 48\enspace {\upmu }\mathrm{g}$ to be considered statistically significant with a confidence level of 97.7%; time intervals over three and six months were also not significant. The study validates for the first time a methodology capable of measuring mass dynamics of living matter over time, when statistically sound conclusions with measurement uncertainties in the microgram range are required. This opens up a new level of precision mass measurements, which makes the methodology a candidate, e.g., for the verification of the principle of mass conservation in the life-sciences.

Comparison of volume measurements of mass standards at low pressures and in liquids

The determination of the volumes of mass standards is key to the precise determination of their masses, due to the effect of the air buoyancy force. The buoyancy force can either be reduced by mass determination at low pressure or enlarged for a determination of the apparent mass using a vessel filled with liquid. The standard method for the volume calibration of weights is comparison in liquid, as described in the document OIML R111. This report presents the results of calibrating the volumes of stainless-steel mass standards with a nominal mass of 1 kg at low pressure and in a liquid. The authors showed that both methods produced comparable results with maximum differences of 0.002 cm3 when adjusted for a standard temperature of 20 °C. The typical uncertainty in the volumes given by both methods is 0.002 cm3. A major source of uncertainty is the volume of the reference weight. The authors conclude that both methods produce consistent results, so that the method of volume calibration at low pressure can be used instead of hydrostatic weighing. The advantage of this approach is that both the masses and volumes of the weights are measured using the same mass comparator, which requires less manipulation. This study will help to establish the procedures for the dissemination and transfer of the mass unit from vacuum to ambient conditions in the institute of the author.

AFRIMETS key comparison (AFRIMETS.M.M-K7) of five stainless steel mass standards: 5 kg, 100 g, 10 g, 5 g and 500 mg

Main textThis key comparison is based on a decision of TCM of AFRIMETS on July 2015 in South Africa. TCM agreed that NIS-Egypt will pilot this comparison by providing the technical support and contributing to the link to the CCM comparison. The comparison consisted of one set of five stainless steel mass standards with nominal values: 5 kg, 100 g, 10 g, 5 g and 500 mg. These masses are owned by the LPEE-LNM and chosen to be the transfer mass standards. The pilot laboratory (NIS) measured the volume and the magnetic properties of the standards before the circulation and had reported these values to the participants. The pilot laboratory has also verified the stability of all travelling standards for one year.Six laboratories measured the set of travelling standards between September 2018 and December 2019.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Macroscopic and microscopic characterizations of Portevin-LeChatelier effect in austenitic stainless steel using high-temperature digital image correlation analysis

Using digital image correlation (DIC) analysis in an Fe-19Cr-13Ni-0.2C austenitic stainless steel (mass%), the tensile deformation behavior accompanied with the Portevin-LeChatelier (PLC) effect was investigated at high temperatures of 723-823 K under various applied strain rates of 10−4 s−1–5 × 10−3 s−1. With the help of the DIC analysis, the global strain in the gauge part of a tensile specimen and the local strain in a PLC band were precisely measured regardless of the lowering machine stiffness at a high temperature. The high-temperature DIC analysis could identify the critical strain and strain rate conditions where stress-strain curve indicated serrated flow. The analytical results revealed that dynamic strain aging in the austenitic stainless steel was controlled by the pipe diffusion of Cr atoms. Further, it was also confirmed that the local strain gently increased in a gauge part through a PLC band propagation, which promoted a repeatable A-type PLC band propagation in the same direction. Furthermore, the local strain was discontinuously developed by the repeatable formation of PLC bands; consequently, the local strain rate became remarkably high within a PLC band. In addition, the local strain rate in the PLC band monotonically increased with the increase in the number of PLC bands. From this viewpoint, it was discovered that necking deformation occurs suddenly at the PLC band, when the local strain rate exceeds the critical value, where dynamic strain aging is ineffective.

The upgrade of NIM-2 joule balance since 2017

In 2017, we published the first measurement result with the NIM-2 joule balance and the relative standard uncertainty was 2.4 × 10−7. Since then, a series of improvements have been carried out to upgrade the NIM-2 joule balance towards the 10–8 level relative uncertainty. The main improvements include a permanent magnet, as well as a two-layer magnetic shield to decrease the main uncertainty contribution from the external magnetic field, a parasitic displacement measurement system and a new suspension for improving alignments, and a new mass translation stage constructed with all non-magnetic materials. In September 2019, when the NIM-2 joule balance was used to calibrate a 1 kg mass, the type A relative standard uncertainty had been reduced to 3 × 10−8(k= 1) and the combined relative standard uncertainty was less than 1 × 10−7(k= 1). In October and November 2019, a 1 kg Pt/Ir mass and a 1 kg stainless steel mass were measured with the NIM-2 joule balance, and the relative standard uncertainties were 5.2 × 10−8 and 6.5 × 10−8, respectively. The relative difference between the measured values and the calibration values obtained from the mass group were 4 × 10−9 and 3 × 10−8, respectively.

Final report for GULFMET.M.M-K4: key comparison of 1 kg stainless steel mass standards

This report summarizes the results of the key comparison (KC) carried out among eight National Metrology Institutes (NMIs) and an Accredited Calibration Laboratory, six of which are member countries of Gulf Association for Metrology (GULFMET). The KC of two 1 kg stainless steel knob weights was decided during the 11th meeting of GULFMET TC Mass held in Abu Dhabi, 2017. TÜBİTAK UME (Turkey) acted as pilot laboratory. The comparison was linked to CCM.M-K4 via INRIM (Italy), METAS (Switzerland), KRISS (Republic of Korea). The results were evaluated by the generalized least square (GLS) estimation. Majority of results were consistent with each other and with the key comparison reference value of CCM.M-K4 within their expanded uncertainties with the coverage factor of k = 2.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report on EURAMET comparison on 1 kg stainless steel mass standards

In order to demonstrate the equivalence in calibration of mass standards among National Metrology Institutes (NMIs) of EURAMET this key comparison (KC) on 1 kg stainless steel mass standards has been carried out under the auspices of EURAMET. The comparison was undertaken with reference to the International Prototype Kilogram (IPK) as the definition of the unit of mass. The overall result shows good consistency among the participants.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Research on Forming Temperature of Metastable Austenitic Stainless Steel Head Based on Strain-Induced Martensitic Transformation

The formation of strain-induced martensite (SIM) is found in metastable austenitic stainless steel (m-ASS) during cold forming, and the presence of SIM may cause reductions in toughness, ductility, and corrosion resistance of m-ASS. These mechanical properties can be restored and improved by proper heat treatment after forming, however, which obviously raises the manufacturing costs. One low-cost way to reduce the SIM amount during m-ASS forming is to maintain the forming temperature at an appropriate level. This paper intends to investigate an approach to determine the optimum forming temperature at which the strain-induced martensitic transformation (SIM-Tr) of m-ASS head during forming can be restrained within a limited intensity. First, static tensile tests were conducted on S30408 conventional cylindrical tensile specimens under different temperatures varying from 20 °C to 180 °C, and then the effect of deformation temperature on SIM was evaluated. Second, according to the stacking fault energy (SFE) calculation method, m-ASS's chemical composition was taken into further consideration to investigate its effect on SIM. Finally, a formula was established based on SIM and chemical composition for optimization of forming temperature. In addition, the results obtained by this formula were compared with those of the experiment by S30408 ASS head stamping tests, and the satisfactory matching is found for the proposed forming temperatures and predicted ferrite number (FN) values (readings of the Ferritescope measurement, as a representation of the amount of martensite in this study). Furthermore, an enhancement in the cryogenic impact properties and a fewer quantity of delta-ferrite in the microstructure of m-ASS heads are observed when warm stamping is performed as compared with the cold stamped head.

GULFMET M.M-S1: Comparison of mass standards in multiples and sub-multiples of the kilogram

In order to show metrological equivalence in mass standards calibration among National Metrology Institutes (NMIs) of member countries of the "Gulf Association for Metrology" (GULFMET), the first organized supplementary comparison (SC) of mass standards have been carried out under the auspices of the GULFMET. This supplementary comparison of 10 kg, 500 g, 20 g, 2 g and 100 mg stainless steel mass standards was based on the decision of the GULFMET meeting held in 2013. TÜBİTAK-UME (Turkey) acted as pilot laboratory. In this region only two NMIs have the CIPM-MRA signature. These NMIs are SASO-NMCC (Saudi Arabia) and EMI (Abu Dhabi). Therefore, the reference values were calculated with the weighted mean method using these two participating laboratories. Concerning the weight of 100 mg, the weight has not been evaluated in this comparison because the travelling standard was mixed-up at some point during the artefact circulation. The results of EMI and SASO-NMCC are consistent with the reference values within their expanded uncertainties with the coverage factor, k = 2.KEY WORDS FOR SEARCHreference value, travelling standard, weighted mean method and metrological equivalenceMain textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

ELLIPSOMETRIC STUDIES OF SURFACE LAYERS FORMED ON STAINLESS STEEL MASS STANDARDS

Three stainless steel mass standards of different grades each of mass 100 g were studied under normal ambient conditions by ellipsometry to determine the surface layers formed on them. The studied specimens are of grades E1, E2, and F1. The factors influencing the thickness of the surface layers were discussed. It was observed that the thicknesses of formed layers on different mass standards were not equal. The estimated values of the oxide and water layers range between 1 nm and 5 nm.

Numerical simulation of complex flow and heat transfer induced by localized laser heating on a urethane-coated substrate

ABSTRACTA three-dimensional numerical simulation is conducted for complex flow and heat transfer that incorporate solid–liquid–vapor phase change and surface chemical reaction induced by localized laser heating on a urethane-coated stainless-steel substrate. The surface chemical reaction due to laser irradiation on the urethane-coated stainless-steel substrate, and heat and mass transfer due to melting/vaporization of the stainless steel are considered. The entire problem is solved within one computational domain that includes two solid regions and one gaseous region through a penalty method. One of the solid region is the paint that will decompose via chemical reaction to generate gaseous products and then mix with the air, and the other one is the stainless steel that melting and vaporization can occur due to extremely high temperature in the process. Moreover, the gas phase is considered as a multicomponent system that consists of O2, N2, CO2, H2O, NO2, binder vapor, and stainless-steel vapor. In the present multiphysics simulation, the process of melting, vaporization and chemical reaction and the splash of the melted paint and stainless steel into the gas is observed.

The final report for APMP.M.M-K6.1: key comparison of 50 kg stainless steel mass standard

This report describes the result of an Asia Pacific Metrology Programme (APMP) regional comparison of 50 kg stainless steel mass standard carried out among three laboratories as a collaboration among inter-Regional Metrology Organization (RMO) programs. One weight of nominal value 50 kg has been prepared by CENAM (Mexico) of Sistema Interamericano de Metrología (SIM) for this APMP comparison as an international collaboration. The reported results by participants are consistent with each other and with the key comparison reference value (KCRV) of comparison, CCM.M-K6 to which this comparison has been linkedKEY WORDS FOR SEARCHMass standardMain textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Determination of volume of stainless steel weights

This report describes the results of a supplementary comparison between SIM NMIs, which is being carried out in order to compare the degree of equivalence in volume measurements of stainless steel mass standards.For this comparison was selected a set of weights, with the following nominal values: 2 kg, 1 kg, 200 g and 1 g.KEY WORDS FOR SEARCHDensity, volume, weights, 2 kg, 1 kg, 200 g, 1 g, supplementary comparison, SIM, CENAM, INACAL, INM, INEN, INTN and LACOMET.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report of AFRIMETS.M.M-S6: supplementary comparison of 100 mg, 100 g 500 g, 1 kg and 5 kg stainless steel mass standards

This report summarizes the results of AFRIMETS.M.M-S6 mass standards comparison conducted between eleven participating laboratories/countries. Two sets of five weights with nominal values 100 mg, 100 g, 500 g, 1 kg and 5 kg were used as the traveling standards. These nominal values were decided from the needs of participating laboratories submitted to the pilot laboratory through a questionnaire and agreed upon by all participants. The traveling standards were hand carried between laboratories starting from February 2014 and were received from the last participants in October 2014. The programme was coordinated by National Metrology Institute of South Africa (NMISA), who provided the travelling standards and reference values for the comparison. The corrections to the BIPM as-maintained mass unit [5] have insignificant influence on the results of this comparison.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

On a Recent Quantitative Framework Examining the Critical Factors for Localized Corrosion and Its Impact on the Galvele Pit Stability Criterion

A quantitative framework examining the Galvele pit stability criterion in the context of repassivation using information from experiments on 1D stainless steel artificial pit electrodes and mass transport modeling is discussed. The framework is built principally upon three studies that have systematically evaluated the critical electrochemical conditions describing the transition of a corroding surface from active dissolution to repassivation. First, the applicability of the Galvele pit stability product for the interpretation of the results of artificial pit experiments was assessed by analyzing the 1D flux as a function of pit geometry, which delineated the parameter space for appropriate data collection and analysis. Mass transport modeling of the 1D pit in combination with experimental measurements of the pit stability product and the repassivation potential provided an estimate of the critical concentration of metal ions at the corroding surface of the pit as it transitioned from stability to repassi...

Final report on APMP.M.M.K4.1—bilateral comparison of 1 kg stainless steel mass standards between KRISS and A*STAR

This report describes a bilateral comparison of 1 kg stainless steel mass standard between the Korea Research Institute of Standards and Science (KRISS), and the National Measurement Centre, Agency for Science, Technology and Research (A*STAR), Singapore, which is registered in the BIPM KCDB as APMP.M.M-K4.1. This nominal value was chosen as it followed the nominal value of CCM.M-K4. This bilateral comparison was piloted by KRISS. The transfer weight was delivered to A*STAR from KRISS in April 2015 and received back from A*STAR in October 2015. A*STAR are aiming to improve their calibration measurement capability (CMC) for mass of 1 kg. KRISS participated in both this comparison and CCM.M-K4, providing a link between the A*STAR result and the KCRV of CCM.M-K4. The final report of this comparison is given in this document.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The final report for CCM.M-K7: key comparison of 5 kg, 100 g, 10 g, 5 g and 500 mg stainless steel mass standards

In order to show equivalence in mass standards calibration among National Metrology Institutes (NMIs) of member countries of the "Comité international des poids et mesures" (CIPM), key comparisons (KC) of mass standards have been carried out under the auspices of the "Comité Consultatif pour la Masse et les Grandeurs Apparentées" (CCM). This key comparison of 5 kg, 100 g, 10 g, 5 g and 500 mg stainless steel mass standards was based on the decision of the CCM during the 12th meeting held in 2010 at the Bureau International des Poids et Mesures (BIPM). KRISS (Republic of Korea) and PTB (Germany) acted as pilot laboratory and co-pilot laboratory, respectively. The results were evaluated with the Monte Carlo method using measurement values based on participants' reference standards calculated following the recent BIPM amendments in 2015. Regarding participant results, VNIIM (100 g and 5 g) were not consistent with the key comparison reference values within their expanded uncertainties with the coverage factor, k = 2.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).