1、INTERNATIONAL STANDARD IS0 7528 First edition 1989-10-15 Nickel alloys - Determination of iron content - Titrimetric method with potassium dichromate Alliages de nickel - Dosage du fer - M VI is the volume, in millilitres, of the potassium dichromate solution, used in the determination; c is the act
2、ual concentration, expressed in moles of l/6 K 0,055 65 is the mass, in grams, of iron corre- sponding to I,00 ml of potassium dichromate solution, c(1/6 K2Cr207) = 1,000 mol/l; m is the mass, in grams, of the test portion. 8.2 Precision 8.2.1 Laboratory tests Fourteen laboratories in six countries
3、participated in the inter- laboratory testing of methods for the analysis of nickel alloys. Of these, nine reported a complete set of results for this Inter- national Standard. Five samples of nominal composition given in table 2 were analysed in duplicate on different days. Table 2 - Nominal compos
4、ition of test samples % (m/m) Sample reference Al co 825 02 0,07 !I02 0,4 0.05 3 920 0,15 2 3 927 Or1 1 7049 1 0,Ol Cr cu Fe Mn 21 1,6 30 0,7 5 604 48 0,4 19 O,l 3 0,3 20 0.05 44 0,4 15 0.15 7 0,8 Ni Remainder Remainder Remainder Remainder Remainder Si Ti 0.4 1.1 0.35 23 3.6 23 088 0,6 0.3 2,s Copyr
5、ight International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ISO7!529:1999(E) 8.2.2 Statistical analysis 8.2.2.1 Results from the inter-laboratory test programme were evaluated according t
6、o IS0 5725 using the means of the duplicate results. The data were tested for statistical outliers by the Cochran and Dixon tests given in IS0 5725. 8.2.2.2 The principle of the Cochran test is that a set of results is an outlier if the within-laboratory variance is too large in relation to others.
7、Dixons test is to determine if the mean from a laboratory is too far from the other laboratory means. Both tests were applied at the 95 % confidence level. 8.2.2.3 Repeatability and reproducibility were calculated ac- cording to IS0 5725 at the 95 % confidence level. Results of the statistical analy
8、sis are given in table 3. 8.2.2.4 No results were rejected as outliers. 9 Test report The test report shall include the following particulars : a) the reference of the method used; b) the results of the analysis; c) the number of independent replications; d) any unusual features noted during the ana
9、lysis; e) any operation not included in this International Stan- dard or regarded as optional. Sample reference 625 902 3920 3627 7649 Table 3 - Results of statistical analysis % h/m)1 Mean Within-laboratory Between-laboratory standard deviation standard deviation Repeatability Reproducibility a= 0,
10、136 0,262 0.39 039 47.77 0,067 0,226 0,24 OM 3800 0,015 0,011 0,043 0,052 44,03 0,102 0,330 0,29 0,96 7.01 0,027 0.086 0,075 0,25 4 Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license fro
11、m IHS-,-,-IS0 7528 : 1888 (El Annex A (informative) Examples of composition of some nickel alloys The examples of compositions given in table A.1 are not to be interpreted as specifications for chemical compositions. Table A.1 - Examples of composition of some nickel alloys % (mlm)ll) Fe Mn MO Ni P
12、Alloy*) Al B C Co3) Cr Cu S Si Ti Others A - - 0,30 - - 28,0 2.5 2,0 - 63,04) - 0,025 0.5 - - 34,0 - - - - 0,15 - 14,0 0,5 60 I,0 - 72,04) - 0,015 0,5 17,0 10,o 0.4 - 0,08 - 14,0 0,5 5,O 1,o - 70,04) - 0,015 0,5 2,2 Nb plus Ta 180 17,0 Q,O 2.8 0,7 to I,2 0.2 0,006 0.08 - 17,o 0,3 Remainder 0,4 2,8 5
13、0,O 0,015 0,015 0,4 0,6 Nb plus Ta W3 21,0 3,3 55,0 1.2 4,7 to 5,5 0.15 0,lO - - - IQ,0 0.7 Remainder I,5 - 30,o - 0,015 1.0 0,15 O,N 23,0 35.0 0,m - - 0,08 5.0 18,0 0.5 5.0 1.0 - Remainder4) - 0,020 1,o 0,2 Pb 0,15 21,0 0.6 0,005 18 0,020 0.13 15,0 18,O 0,2 I,5 l,o - Remainder - 0,915 1.0 2,0 Zr zo
14、 21,0 21,o 3,O 0,15 4,5 0,003 0,12 18,0 14,0 0.2 1.0 l,o 4,5 Remainder - 0,015 I,0 0,Q Zr 4,Q 0,010 0,17 22,0 15,7 5,5 1,5 0,15 0.3 0,005 0,04 19.0 19,0 0,2 0,7 0,6 5.6 Remainder - 0,007 0.4 I,9 Ti plus Al W3 0,08 21.0 21,o 6.1 24 2,4 to 2,8 - - 0,02 I,0 I,0 - TO 13 26,0 Remainder41 0,040 0,035 0,l
15、- - 30,o K L 12 jr3 - 0,003 0,02 12.0 18,O 0.1 2.0 1.0 3.5 Remainder 0,015 0,015 0.1 2.8 Zr 0,010 0,IO 15,0 21.0 5,O 3,3 0,02 to 0,08 - 0,02 2,5 14,5 - 4,O 18 15,0 Remainder 0,040 0,035 0.08 - v 0,35 16,5 7,O 17,0 w 3,0 to 4,5 I) Single values are maximum limits, except for nickel, where single valu
16、es are minimum. 2) Alloy letters are used instead of commercial names until a neutral IS0 designation is developed. 3) Where no limits are given, cobalt is up to a maximum of I,5 % (m/ml. 41 Cobalt counts as nickel in some alloys. 5 Copyright International Organization for Standardization Provided b
17、y IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 7929 : 1999 (El UDC 543.24 : 969.245 : 949.72 Descriptors : nickel, nickel alloys, chemical analysis, determination of content, iron, volumetric analysis. Price based on 5 pages Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
