GOST 21132.1-98
GOST 21132.1−98 Aluminium and aluminium alloys. Methods for determination of hydrogen in solid metal-vacuum-heating (with Change No. 1)
GOST 21132.1−98
Group B59
INTERSTATE STANDARD
ALUMINUM AND ALUMINUM ALLOYS
Methods for determination of hydrogen in solid metal-vacuum-heating
Aluminium and aluminium alloys.
Methods for determination of hydrogen in solid metal by vacuum hot extraction
ISS 77.040*
GST 17 3230
_______________
* In the index «National standards» 2008 ACS
Note the manufacturer’s database.
Date of implementation 2000−01−01
Preface
1 DEVELOPED by JSC «Russian Institute of light alloys» (JSC VILS), the Interstate technical Committee for standardization MTK 297 «Materials and semi-finished products of light alloys"
INTRODUCED by Gosstandart of Russia
2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 14−98 dated November 12, 1998)
The adoption voted:
| The name of the state | The name of the national authority standardization |
| The Republic Of Azerbaijan | Azgosstandart |
| The Republic Of Armenia | Armastajad |
| The Republic Of Belarus | Gosstandart Of Belarus |
| Georgia | Gosstandart |
| The Republic Of Kazakhstan | Gosstandart Of The Republic Of Kazakhstan |
| Kyrgyz Republic | Kyrgyzstandart |
| Russian Federation | Gosstandart Of Russia |
| The Republic Of Tajikistan | Tajikistandart |
| Turkmenistan | The main state inspection of Turkmenistan |
| The Republic Of Uzbekistan | Standards |
| Ukraine | Gosstandart Of Ukraine |
3 Resolution of the State Committee of the Russian Federation for standardization and Metrology, dated April 21, 1999 No. 132 inter-state standard GOST 21132.1−98 introduced directly as state standard of the Russian Federation from January 1, 2000
4 REPLACE GOST 21132.1−81
The Change N 1, approved and put into effect in the territory of the Russian Federation by the Order of Rosstandart dated
Change No. 1 made by the manufacturer of the database in the text IUS N 6, 2008.
1 Scope
This standard specifies two methods of determining hydrogen in a solid metal aluminum and aluminum alloys: a method of vacuum heating analyzer pressure method and vacuum heat mass spectrometric analyzer in dynamic mode (when the mass fraction of hydrogen from 0.06 to 0.7 million).
2 Normative references
The present standard features references to the following standards:
GOST 1012−72 aviation Gasoline. Specifications
GOST 1790−77 alloy Wire T chromel, alumel, Copel and Constantan for thermoelectrodes of thermoelectrical transducers
GOST 3118−77 hydrochloric Acid. Specifications
GOST 4658−73 Mercury. Specifications
GOST 5556−81 Wool medical hygroscopic. Specifications
GOST 9293−74 Nitrogen gaseous and liquid. Specifications
GOST 10484−78 hydrofluoric Acid. Specifications
GOST 18300−87 ethyl rectified technical. Specifications
GOST 25086−87 non-ferrous metals and their alloys. General requirements for methods of analysis
3 General requirements
3.1 General requirements for methods of analysis GOST 25086 with the Supplement.
3.1.1 Mass fraction of hydrogen in the analyzed alloys are determined on two samples one sample, weighted with the error not more than 0.01 g For the result of the analysis be the arithmetic mean of results of two parallel measurements.
4. the Method of vacuum heat analyzer according to the pressure in the accumulation mode
4.1 the essence of the method
The method is based on extraction of hydrogen from the test of metal is heated below the melting point in the range of 500 to 600 °C in vacuum under residual pressure (6,65-of 9.31)·10PA.
Evolved gases are collected in a calibrated volume, the pressure change is determined by their number. Hydrogen from the gas mixture are removed by diffusion through a heated palladium filter, and the differential pressure determine the amount of hydrogen in the extracted gas mixture.
4.2 Preparation of samples for analysis
4.2.1 From billet (samples) width and thickness of at least 10x10 mm, length 70 to 130 mm are machined two samples with a diameter of (8,0±0,1) mm, length (20,0±0,5) mm in the following way:
— face piercing holes of the workpiece along the length of a diameter of 8.5 mm;
— hold finishing end;
— carry out final machining of the sample power feed caliper. The spindle speed should be 1200 to 1500 rpm, the feed value of the caliper from 0.04 to 0.10 mm per revolution of the spindle, cutting depth — from 0,1 to 0,2 mm. the Cutting edge of the cutter is pre-polished with diamond paste. Sharpening angles of the cutter are selected experimentally depending on the brand of alloy. The turning is carried out without cooling the emulsion;
— cut samples with a length of (20,0±0,5) mm each. It is not allowed to support them with tweezers in order to avoid changes in the quality of the surface. It is necessary that each sample falling in a glass buxu located under the workpiece;
— each sample is clamped in the cartridge in the plastic collet and grind the second side. As the material of the collet is also allowed to use Teflon or tarname.
(Changed edition, Rev. N 1).
4.2.2 Samples weighed. Immediately after weighing, the samples shall be placed in the feeder tube installation. It is allowed to leave samples in the air-no more than 3 hours.
4.3 Apparatus reagents and materials
The installation of a vacuum heat pressure analyzer to determine the mass fraction of hydrogen (figure 1) with remote control, consists of the main Assembly units and elements:
— 15 electric resistance furnace providing heating temperature from 300 to 900 °C, equipped with a chromel-aluminium thermoelectric Converter according to GOST 1790 and potentiometer type KSP-4 to measure and record temperature;
— vacuum system with which to install create vacuum (6,65-of 9.31)·10PA; this includes the roughing pump 14 of the type 2НВР-5ДМ, prototy diffusion pump 13 of the type Н50Р, glass prototy pump 4 and the glass tubing;
glass extraction unit, which consists of quartz replacement of the extraction tube 1 (figure 2A), connected with a water-cooled cone 2 with a feed tube 3;
analytical system consisting of a calibrated vessel, bounded on one side of the conditional median line of the glass protochnogo pump 4, on the other — mercury shutter 11. Extracted from the sample gas is pumped into a calibrated container, comprising a cylinder 8, of glass prostudnym pump 4;
— palladium filter (tube outer diameter 2.5 mm, length 100 mm, wall thickness 0.1 mm) with an oven heat 7, which serves to remove hydrogen from the extracted mixture, which is in the analytical system when it is heated to a temperature of from 600 to 700 °C;
— compression gauge Mac-Leod 9 with a measurement range from 1.33·10to 79.8 per PA for pressure measurement collected in an analytical gas system;
— cranes and
with which carried out the lifting and lowering of the mercury in the manometer Mak-Lead 9 and the gate 11 when connecting them alternately with the atmosphere or a backing cylinder 12;
trap 5 and 6 capillary trap, cooled with liquid nitrogen; are used for freezing the water vapors in the installation;
— manometric lamp 10 of the type PMT-2 for control of vacuum.
Figure 1 — schematic of the vacuum heating analyzer pressure
Figure 1 — schematic of the vacuum heating analyzer pressure
Figure 2 — Extraction tube
a — tube without a liner; b — tube with liner
Figure 2 — Extraction tube
Allowed the use of other analytical equipment, including a comprehensive analysis by the same method and provides obtaining of metrological parameters established by this standard.
Mercury metal according to GOST 4658.
Gasoline according to GOST 1012.
The technical rectified ethyl alcohol according to GOST 18300.
Oil vacuum.
Rubber vacuum.
Hydrochloric acid according to GOST 3118, a solution of 1:9.
Hydrofluoric acid according to GOST 10484.
Liquid nitrogen according to GOST 9293.
Medical absorbent cotton wool GOST 5556.
Baptiste.
State standard samples of composition of aluminum alloys on state: N 6007−91, 5060−89, 3263−91П, 7084−93, 7085−93, 7219−96, 7220−96, 7804−2000, 8844−2006. Allowed the use of newly manufactured standard samples with certified mass fraction of hydrogen from 0.06 to 0.7 million.
(Changed edition, Rev. N 1).
4.4 analysis
4.4.1 Checking the vacuum valves are free, with no effort to rotate. All the cranes need not less than twice a month to change vacuum grease, which is applied in a thin layer. The lubricant must not get into the vacuum of communication.
4.4.2 Load of the analyzed samples in the feeder tube 3 (figure 1). In one series download no more than ten samples.
4.4.3 Applied vacuum grease to the cone of the extraction tube 1 and grind it to a water cooled cone 2. Do not allow vacuum grease on the inner surface of the quartz tube.
4.4.4 For pre-evacuating throughout the installation, you must:
— close all faucets;
— turn on the roughing pump 14;
— tap to join with a backing cylinder 12 and to pump air out of it for 15−20 minutes; close the faucet
and the taps
,
and
connect the high-vacuum manifold pumping through Protochny diffusion pump 13.
In this position of the valves air is evacuated from the extraction tube 1 and parachutage diffusion pump 13 to create a negative pressure of not less than 1.33 PA. The vacuum control lamp 10;
— close all faucets. The crane is connected to the trunk of the faucet
and gently open the tap
, combining analytical system with a backing pump. The mercury in the manometer Mak-Lead mercury 9 and the gate 11 will rise. The mercury must be lowered by connecting the taps
and
with a backing cylinder 12. Pumping is carried out to create a negative pressure of not less than 1.33
PA.
4.4.5 To create throughout the system a high vacuum is necessary:
— include water cooling prostudnyh diffusion pumps 4 and 13 and the cone 2;
to enable heating prostudnyh diffusion pumps 4 and 13;
— taps ,
and
connect with parachute diffusion pump 13 and after 10 minutes, turn on the pump, the trap 5 pour liquid nitrogen. Pumping is carried out to create in the vacuum system not less than 1.33·10
PA. The degree of dilution is controlled by a pressure bulb and manometer 10 Mac-Leod 9.
4.4.6 Conduct degassing the extraction tube 1. To do this, pull the electric resistance furnace to the tube and turn it. Temperature degassing (900±20) °C, duration 1 h
4.4.7 Determine the correction control of the experience, which should not exceed 7·10cm
/h with the volume of the analytical system 1000 cm
. To do this, reduce the oven temperature to operating and measure the leakage in the analytical system. The temperature of the analysis set at 30−40 °C below the melting temperature of the analyzed alloy.
Pour liquid nitrogen in the capillary trap 6, the tap connected to the analytical system via prototy diffusion pump 4, raise the mercury in the bolt 11. After 20 min (the duration of the measurement amendments in the reference experiment) measure the pressure in the analytical system.
(Changed edition, Rev. N 1).
4.4.8 After the correction of the reference experiment, the mercury in the shutter 11 is omitted and analytical system the extraction tube, a high vacuum.
4.4.9 For analysis of the sample raise the mercury in the bolt 11, discard the test sample in the extraction tube 1 steel pusher with a magnet. 40 min measure the pressure in the test system pressure gauge Mack-Leod 9 and continue measuring every 10 min the Extraction is complete when three consecutive measurements of pressure are the same or change to the adjustment value control experience. Extraction of hydrogen from a sample taken size lasts from 1 to 2 h. the pressure Value of the last measurement recorded in the work log.
Using a crane connect the extraction pipe line pumping protochnogo diffusion pump 13 and the heating furnace include palladium filter 7. The hydrogen diffuses through the walls of the palladium tube, and the pressure in the test system decreases. At the same time remove the sample from the hot zone of the extraction tube.
4.4.10 after the removal of hydrogen from a gas mixture (the results of three pressure measurements conducted every 10 min) measure the residual pressure in the analytical system, turn off the oven heat the palladium filter 7. The crane is
connected to the analytical system, and lower the mercury in the slide 11 and pose the analytical system of high vacuum.
4.4.11 Analysis of the remaining samples of the series is carried out, as specified in 4.4.9,
Before analysis of each sample, you must define the amendment in the reference experiment, as specified
4.4.12 For the analysis of aluminium alloys containing components with a high vapor pressure, in an extraction tube 1 drop the first one («blank») sample of a series, placed above the sample with a magnet a steel ball in a quartz shell and carry out degassing the sample for 1 h at the temperature of analysis. At the end of the analysis the sample is removed from the heating zone in the process of the extraction tube by turning it in the socket 2. Then determine the correction control experience in 4.4.7 and analyze the following samples in accordance with 4.4.9 and
Note — degassing the «blank» of the sample due to the necessity of removing the moisture adsorbed on the walls of the extraction tube, the interaction of which with sublimate hydrogen is formed, distorting the results of the analysis. To prevent the spread of sublimates across the surface of the tube is a quartz bead (figure 2), which is used in the analysis of each sample containing the components with high vapor pressure.
4.4.13 For the analysis of the other sample series carry out the following operations.
4.4.13.1 turn Off the electric resistance furnace 15 and after 20 minutes close the taps that
.
4.4.13.2 Off glass prototy 4 pump and vaporize liquid nitrogen, compressed air from the trap 5. Vacuum in the analytical system is reduced due to the evaporation of moisture condensed on the trap. Pumped to the analytical system through Protochny diffusion pump 13 to create a high vacuum, and then close the valve .
4.4.13.3 Off prototy diffusion pump 13 and after 10 min to evaporate the liquid nitrogen from the trap 5. After 15 minutes close the valve . After 30 min after switching off the diffusion pump protochnogo shut off the water.
4.4.13.4 turn Off the roughing pump 14 and the pump letting in air through the valve , connecting it with the atmosphere.
4.4.13.5 In low vacuum, the highway through the faucet to let the air of the atmosphere.
4.4.13.6 Taps and
connect the extraction tube 1 with the low vacuum line and disconnect it from the water-cooled section 2.
Load a new batch of samples.
4.4.14 When the machine is switched off when the series of samples analyzed is loaded not completely, carry out the operations specified
4.4.15 Air into the analytical system and prototy diffusion pump 13 is admitted only when the total preventive maintenance installation and Troubleshooting.
4.4.16 After conducting each series of tests for the removal of exhalations, remaining on the walls of the extraction tube, it is filled with water and kept for 5−7 minutes and Then the tube filled with a solution of hydrochloric acid 1:9 and allowed to stand until complete removal of the sublimate, and then washed with distilled water.
If the sublimates are removed, then after processing of the tube with hydrochloric acid you should rinse it under running water and fill hydrofluoric acid, to stand for 3−5 min until complete removal of the sublimate, and again, flush, then distilled water.
Washed up is calcined in an electric furnace of the resistance at the temperature of (900±20) °C for 30 min.
4.5 Processing of results
4.5.1 Mass fraction of hydrogen in the analyzed sample , mn
, is calculated by the formula
where 
;
— mass fraction of «surface» of hydrogen, corresponding to a sample of this alloy data size, million
.
The total mass fraction of hydrogen 
, is calculated by the formula
where is 0.89, the coefficient mn/cm
;
— the volume of the analytical system, cm
;
— indoor temperature, °C;
— pressure of hydrogen in the analysis, PA:
and
the total and residual pressure during the analysis, PA;
the hydrogen pressure during the control of experience, PA;
— analysis time, min;
1013 — factor, PA; — the mass of sample, g.
(Changed edition, Rev. N 1).
4.5.2 To determine the mass fraction of the «surface» of the hydrogen formed by the interaction of moisture adsorbed on the sample surface with a metal at the temperature of analysis, rod of aluminum or aluminum alloy with a diameter of 10−12 mm is placed in a quartz tube and degassed at the temperature of analysis, 10−15 h in vacuum to remove dissolved in the metal hydrogen.
From bar machined samples and analyze as specified in 4.4.7−4.4.10.
Mass fraction of «surface» hydrogen , mln
, corresponding to sample data sizes, calculated by the formula (2).
The average value of the mass fraction of «surface» hydrogen for each grade of alloy and the sample size taken is determined from analysis of 15−20 samples held in parallel.
Determination of the mass fraction of the surface hydrogen can be carried out by loading in each batch of analyzed samples degassed sample of the same brand of alloy.
(Changed edition, Rev. N 1).
4.5.3 discrepancies in the results must not exceed the values given in table 1.
Table 1
In million
| Mass fraction of hydrogen | The absolute maximum discrepancy | |
| results of parallel measurements |
the results of the analysis | |
| From 0.06 to 0.13 incl. |
0,03 | 0,04 |
| SV. 0,13 «0,22 « |
0,04 | 0,06 |
| «0,22» 0,31 « |
0,04 | 0,07 |
| «0,31» 0,45 « |
0,05 | 0,08 |
| «0,45» 0,70 « |
0,07 | 0,10 |
5 a Method for vacuum-heat with a mass spectrometer analyzer in dynamic mode
5.1 the essence of the method
The method is based on extraction of hydrogen when heating a test sample in high vacuum to a temperature below the melting temperature of the alloy (typically 500 to 600 °C) and registration of hydrogen mass spectrometer.
5.2 Preparation of samples for analysis
Use two types of cylindrical specimens: diameter 8 mm, height 20 mm and diameter 10 mm, height 10 mm.
5.2.1 procedure for the preparation of samples with a diameter of 8 mm and height 20 mm —
5.2.2 For producing samples with a diameter and height equal to (10,0±0,1) mm, cut the workpiece width, and thickness 12 mm, length from 40 to 70 mm. Further conduct operations in accordance with
5.3 Equipment, reagents and materials
The mass spectrometer model MX-7203 to determine the mass fraction of hydrogen [1].
Allowed to use other equipment, providing the metrological parameters established by this standard.
State standard samples of composition of aluminum alloys on state: N 6007−91, 5060−89, 3263−91П, 7084−93, 7085−93, 7219−96, 7220−96, 7804−2000, 8844−2006. Allowed the use of newly manufactured standard samples with certified mass fraction of hydrogen from 0.06 to 0.7 million.
A planimeter.
Insert of metallic molybdenum of high purity, containing not less than 99.5% molybdenum. For the manufacture of the liner (figure 3) are machined from a molybdenum rod of cylindrical billet with a diameter (16,0±0,5) mm, height (26,0±0,5) mm, perform a gable ledge and two holes in accordance with figure 3.
Figure 3 — Liner
Figure 3 — Liner
The resulting billet is annealed in a vacuum furnace at a temperature of 1400−1500 °C for 4 h, cooled in vacuum to room temperature.
Billet grind to diameter (14,0±0,5) mm — see figure 3.
The liner is fixed in the lower part of the analytical process of the extraction tube (figure 2B).
Other materials and reagents — 4.3.
(Changed edition, Rev. N 1).
5.4 analysis
Check the position of controls of the mass spectrometer, which shall be those specified in table 2.
Table 2
| Management body |
Position |
| Valves water cooling of the diffusion pump and the extraction tube socket |
Closed |
| All valves in vacuum system |
Closed |
| The switch Network of the voltage stabilizer |
Off |
| The «Network» of the mass spectrometer |
Off |
| Button backing pump |
Off |
| Button scanner «Manual», «ED», «SCAN», «computer" |
Pressed |
| Network digital voltmeter |
Off |
| «GWC"-"UPT" |
Pressed |
| Button «ICD" |
Pressed |
| «Network» LKS |
Off |
| Button «Source — cathode" |
Pressed |
| Solenoid valves 1 and 2 |
Pressed |
| The switch kind of works on the power unit solenoid valve |
«Manual» |
5.4.1 Upload the analyzed samples in the feeder tube.
5.4.2 Applied vacuum grease to the cone of the extraction tube and grind it to a water cooled cone. Do not allow vacuum grease on the inner surface of the quartz tube.
5.4.3 For pre-evacuating throughout the installation, you must:
to supply water to the cooling system of the mass spectrometer;
— toggle switch «Network» of the voltage regulator switch to the on position «On»;
— set the switch to «Network» on the power supply of the mass spectrometer in the On position, this should trigger light alarm «Network» and include light alarm cooling of the diffusion pump;
— turn on the roughing pump button to the «On» position. Simultaneously with the inclusion of parnasos include Network UPT, GUC, ICD and Network LKS.
After reaching the required backing pump on Parnasse (the position of the indicator needle in the green sector of the scale, which corresponds to 10-10
PA) open the valve VH6, creating an extraction tube backing pump.
5.4.4 To create the high vacuum needed:
— close the valve VH6 and VH7 open the valve to drain farrallon before joining the arrows of the indicators of the backing pump of fornessa and farrallon in the green sector (10-10
PA);
to enable heating of the diffusion pump by pressing the button On the graphic control unit vacuum system. When you enable derrasola should turn on his light alarm;
— after 20−25 minutes, when the arrow indicator high vacuum will pass two-thirds of the white sector of the scale, which corresponds to 10-10
PA in the trap of the pumping system to fill liquid nitrogen (approximately one-third volume) and provide a closed high vacuum valves operating vacuum (the arrow is indicator of high vacuum is in the green sector of the scale, which corresponds to 10
-10
PA). After that the trap is fully topped up with liquid nitrogen;
— if the required vacuum in the analyzer and in an extraction system of the mass spectrometer high vacuum to open the valves VH3 and VH4.
5.4.5 Conduct degassing the extraction tube. This resistance furnace pull on the analytical process of the extraction tube and equipped with a programmer of temperature set the temperature degassing at 900 °C. the Duration of degassing is 30−40 min.
5.4.6 Reduce the oven temperature to operating.
5.4.7 Include the ion source by pressing on the power supply, the potentiometer «Issue» define the strength of the emission current is equal to 0.4−0.5 mA. On the panel of the power supply LEDs are displayed in the «SOURCE» and «CATHODE».
5.4.8 Pour the liquid nitrogen in the trap of the analytical system.
5.4.9 Block VH4 high vacuum valve and open the valve VH1, which connects the extraction tube with the analyzer.
5.4.10 Set the attenuator scales «UPT» and switch «MEASURING RANGE» LKS into a position that makes the most convenient entry intensity check hydrogen. The speed of the pullback of the diagram tape needs to be 720 or 300 mm/h.
5.4.11 In manual mode the potentiometer «SCAN START» are set at the maximum of the peak of hydrogen, and then shifted from the maximum peak of the hydrogen in the direction of the sweep to the background level and press the «AUTO» or «SCAN». The record peaks of hydrogen (figure 4) will occur automatically after pressing the button «AUTO». The mass spectrometer can operate in the mode of computers.
Figure 4 — Kinematic curves with a gas-graduation
Figure 4 — Kinematic curves with a gas-graduation
5.4.12 Record peaks of hydrogen on a recording potentiometer was carried out at the position of the switch long sweep 3 or 4.
5.4.13 Magnet removes the ball from the extraction tube, discard the sample in the extraction tube with the pusher, a magnet down the ball and record on the tape LKS kinetic curve of hydrogen evolution (figure 5).
Figure 5 — Kinetic curve for the extraction of hydrogen from a sample
I — the area under the kinetic curve selection «surface» hydrogen , cm
;
II — the area under the kinetic curve of the selection of the analyzed hydrogen , cm
Figure 5 — Kinetic curve for the extraction of hydrogen from a sample
5.4.14 the First sample («blank») from the loaded series is used for degassing the extraction tube by pointing the sublimates. Degassing is complete when reaching a constant value of intensity of allocation of hydrogen. Remove the sample from the extraction tube by turning it by 90°.
5.4.15 After restoring sublimates conduct the graduation mass spectrometer for the determination of the calibration coefficient for hydrogen (see 5.5).
5.4.16 the Analysis of other samples of the series is carried out, as specified in 5.4.10, 5.4.12,
5.4.17 the Extraction is complete when the value of intensity of allocation of hydrogen, equal to the background value or exceeding this value by 10−15% (figure 5). Removal of a sample from the zone of heating —
5.4.18 For the analysis of the other sample series carry out the following operations:
— turn off resistance furnace, remove it from the extraction tube;
— VHI cover the valve and open the high vacuum valve VH4, evaporate the liquid nitrogen from the trap of the analytical system;
— block the valves VH4, VH7;
— turn off the roughing pump and admit air into the extraction pipe, to do this, open the valves VH6 and VH8;
— removed from the cone of the extraction tube and remove vacuum grease from the socket with cotton wool soaked in gasoline;
— put the boot up a new series of samples, the ball pusher;
— applied to the cone vacuum grease, is inserted into the socket of the extraction tube and water-cooled cone and grind;
— close the valve VH8 and create in an extraction tube backing pump, opening the valve VH6;
— close the valve VH6, VH7 open the valve and high vacuum valve VH4 and pumping system for high vacuum. Then do as described in 5.4.5−5.4.17.
5.4.19 the Shutdown of the mass spectrometer is carried out in accordance with the manual.
5.5 Calibrating the mass spectrometer
5.5.1 Mass spectrometers model MX-7203 graduate in pure hydrogen or using standard samples (CO) composition of aluminium alloys with a certified mass fraction of hydrogen.
5.5.2 the Graduation mass spectrometer on pure hydrogen
The calibration coefficient , cm
/cm
, calculated by the formula
where 
;
— initial hydrogen pressure in a calibrated volume, PA;
— calibrated volume, cm
;
— the universal gas constant, cm
·PA/mol·deg;
— indoor temperature, °C;
— the area of the chart under the kinetic curve, see
(figure 4);
— one gram-mole of hydrogen.
The calibration coefficient set as the arithmetic mean of results of three measurements (figure
4).
5.5.3 Calibrating the mass spectrometer according to standard samples
The calibration coefficient is determined using standard samples as follows:
the time series of analyzed samples charged with two standard sample;
— analyzed first in accordance with the manual of the mass spectrometer;
the calibration factor of the mass spectrometer for co , g·mn
/cm
, calculated by the formula
where a certified mass fraction of hydrogen in CO, mn
;
— mass fraction of «high temperature» surface hydrogen for the sample of the alloy, mn
;
— the mass of sample, g;
— the area under the kinetic curve of hydrogen evolution of the co, cm
.
The second one analyzed in case of violation of the mode of operation of mass spectrometer
.
5.6 processing of the results
5.6.1 Mass fraction of hydrogen in the analyzed sample , mn
, is calculated with use of the computer in accordance with the manual of the mass spectrometer.
5.6.2 Mass fraction hydrogen in the test specimen , million
, without the use of computers for graduation FROM calculated by the formula
where is the area under the kinetic curve of hydrogen evolution from the test sample, cm
(figure 5);
— mass fraction of «high temperature» surface hydrogen for the sample of the alloy, million
.
Square measure planimetrically allowed measurement by weighing.
To measure by weighing cut out a square of chart paper with a side of 10 cm, area of 100 cm
, weighed on an analytical balance with an accuracy of at least 0.001 g (weight
). Cut from chart paper the section corresponding square, which is bounded on one side of the curve of hydrogen evolution from the test sample, with the other line of the background (figure 5 — II); weigh this phase diagram tape (weight
) and calculate the area
, cm
, according to the formula
5.6.3 Mass fraction hydrogen in the test specimen , million
, without the use of a computer with graduation in pure hydrogen is calculated by the formula
where 89 — factor, million·g/cm
;
— calibration factor mass spectrometer on pure hydrogen, cm
/cm
.
5.6.4 To determine the mass fraction of «high temperature» of the surface hydrogen is used degassed bars — see
When calibrating the mass spectrometer for pure hydrogen degassed from bars machined samples 4.2.1 and carry out their analysis, as specified in 5.4; mass fraction of «high temperature» of the surface hydrogen , in millions
, is calculated by the formula
where is the calibration factor of the mass spectrometer on pure hydrogen, cm
/cm
;
— the area under the kinetic curve of hydrogen degassed from the test sample, cm
.
The average value of the mass fraction of «high temperature» surface hydrogen for each grade of alloy and the accepted sample sizes determined by the results of parallel analysis of 15−20 samples.
When calibrating the mass spectrometer for the mass fraction of «high temperature» surface hydrogen is determined as follows:
— from the degassed rod and from the rod of a standard sample machined by 4.2.1 two samples, conduct their analysis 5.4;
— define the values of the areas under the kinetic curves of hydrogen evolution, respectively, for THE () and degassed sample (
), as specified in 5.6.2;
— calculate the calibration factor of the mass spectrometer according to the formula
where a certified mass fraction of hydrogen in CO, mn
.
Mass fraction of «high temperature» of the surface hydrogen , in millions
, is calculated by the formula
The average value of the mass fraction of «high temperature» surface hydrogen for each grade of alloy and the accepted sample sizes determined by the results of parallel analysis of 15−20 samples.
5.6.5 discrepancies in the results must not exceed the values given in table 3.
Table 3
In million
| Mass fraction of hydrogen |
The permissible divergence | |
| results of parallel measurements |
the results of the analysis | |
| From 0.06 to 0.13 incl. |
0,02 |
0,03 |
| SV. 0,13 «0,22 « |
0,03 |
0,04 |
| «0,22» 0,31 « |
0,04 |
0,05 |
| «0,31» 0,45 « |
0,05 |
0,07 |
| «0,45» 0,70 « |
0,06 |
0,08 |
Annex a (informative). Bibliography
APPENDIX A
(reference)
[1] THE 25−7401−014−87 Mass spectrometer MX-7203 (Production Association «Electron» — Sumy)
The electronic text of the document
prepared by JSC «Code» and checked by:
the official publication of the
M.: IPK Publishing house of standards, 1999
