ISO 21952:2012 pdf free download.Welding consumables — Wire electrodes, wires, rods and deposits for gas shielded arc welding of creep-resisting steels — Classification.
ISO 21952 was prepared In collaboration with the International Institute of Welding. II recognizes that there are two somewhat different approaches in the global market to classifying a given wire electrode, wire, rod or deposit, and allowe for either or both to be used, to suit a particular market need. Application of either type of classification designation (or of both where suitable) identifies a product as classified in accordance with ISO 21952. The classification in accordance with system A is mainly based on EN 12070:1999111. The classification in accordance with system B is mainly based upon standards used around the Pacific Rim,
ISO 21952 proposes a classification system for wire electrodes, wres and rods in terms of their chemical composition and, where required. in terms of the yield strength, tensile strength and elongation of the all-weld metal deposit. The ratio of yield to tensile strength of weld metal Is generally higher than that of parent metal. Users should note that matching weld metal yield strength to parent metal yield strength does not necessarily ensure that the weld metal tensile strength matches that of the parent material. Where the application requires matching tensile strength. therefore, selection of the consumable should be made by reference to colwnn 4 of Table 2.
It should be noted that the mechanical properties of all-weld metal test pieces used to classify the electrodes. wires and rods vary from those obtained In production joints because of differences In welding procedure such as electrode size, width of weave, welding position and matenal oonosition.
I-ISO 21952 specifies requirements for classification of wire electrodes. wves and rods for gas
shielded metal arc welding and tungsten inert-gas weldmg of creep-resisting steels, and for the. deposits in the as-welded or post-weld heat-treated condition. One wwe electrode can be tested and classified with different shielding gases.
ISO 21952 Is a combined specifIcation providing for classification utitizing a system based upon the chemical composition of wire electrodes, wires and rods with requrements for yield strength and average impact energy of 47 J of all-weld metal, or utilizing a system based upon the tensile strength of the all-weld metal deposits and the chemical composition of wire electrodes, wires and rods.
a) Clauses. subdauses and tables wtucti carry the suffix letter A’ are applicable only to wire electrodes. wires, rods and deposits classified in accordance with the system based upon the chemical composition with requirements for yield strength and the average impact energy of 47.1 of al-weld metal deposits under this International Standard.
b) Clauses. subctauses and tables which carry the suffix letter 9 are applicable only to wire electrodes, wires, rods and deposits dassifled in accordance with the system based upon the tensile strength of all-weld metal deposits and the chemical composition of wire electrodes. wwes and rods under ISO 21952.
c) Clauses. subclauses and tables which do not have either the suffix letter A or the suffix letter “B’ are applicable to all wire electrodes, wires, rods and deposits classified under this International Standard.
2 Normative references
The following referenced documents are indispensable for the application of ISO 21952. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (Including any amendments) applies.
ISO 544, t6fekteig consumables — Technical delivery conditions For filler inatenals and fluxes — Type of product. dirnenss, tolerances and markings
ISO 13916, kllekfing — Guidance on the measurement of preh.aftng temperatwe, intarpaSs temperature and preheat maintenance temperature
ISO 141 752008. Welding consumables — Gases and gas mixtures to, fusion welding and allied processes ISO 14344, Welding consumables — Procurement of feller materials and fluxes
ISO 15792.1, WeldIng consumables — Test methods — Part 1: Test methods b all-weld metal test specimens Er, steel, nickel and nickel alloys
lSOS0000-1:2009, Quantities and units — Pan 1: General
4.3B Classification by tensile strength and chem,cal composition
The symbol for tensile strength for the all-weld metal deposit produced by the gas shielded metal erc weldmg process and the tungsten inert-gas welding process shall be the following:
— 49 for 490 MPa minimum tensile strength;
— 52 for 520 MPa minimum tensile strength;
— 55 for 550 MPa minimum tensile strength;
— 57 for 570 UPa minimum tensile strength;
— 62 for 620 MPa minimum tensile strength;
— 69 for 690 UPa minimum tensile strenh;
— 78 for 780 MPa minimum tensile strength.
The complete mechanical property requirements that shall be fuffitled by the venous compositions are specified in Table 2.
4.48 Classification by tensile strength and chemical composition
The symbols for shielding gases shall be in accordance with ISO 14175:2008, for exerTiple:
— the symbol Ii shall be used when the classification has been performed with shielding gas ISO 14175-lI. 100% argon;
— the symbol M12, for mixed gases, shall be used when the classification has been performed with shielding gas ISO 14175-M12, but without helium;
— the symbol M13 shall be used when the classification has been performed with shielding gas ISO 14175-M13;
— the symbol M20, for mixed gases, shall be used when the classification has been performed with shielding gas ISO 14175-M20, but without helium,
— the symbol M21 • for mixed gases, shall be used when the classification has been performed with shielding gas ISO 14175-M21, but without helkim;
— the symbol Cl shall be used when the classIfIcation has been performed with shielding gas ISO 14175-Cl, carbon dioxide:
— the symbol Z Is used for an unspeof’ied shielding gas.
6 ChemIcal analysis
Chemical analyse shall b. performed on specamens of the wire electrode, wires or rods Any analytical tedinique may be used, but I, case of dispute, reference shall be made to established ptd3lislled methods. In case of chemical elements that do not change during production. chemical analysis of the wire electrode, wires or rods may be substituted by an analysis of product Wi process or raw material or a report of the ladle chenwcal analysis of a raw maleiial,
7 Rounding procedure
For purposes of detemiining compliance with the requirements of ISO 21952, the actual test values obtained shall be subiect to ISO 80000-1:2009, B,3, Rule A, It the measured values are obtained by equipment calibrated In units other than those of ISO 21952, the measured values shall be converted to the units of ISO 21952 before rounding. If an arithmetic average value is to be compared to the requwements of ISO 21952, rounding shall be done only after calailating the arithmetic average. If the lest method cited in Clause 2 contains instructions for rounding that conftc* with the instructions of this International Standard, the rounding requsements of the test method standard shall apply. The rounded results shall fljlfil the requirements of the appropriate table for the dassiflcation under test,
8 Retest
If any test fails to meet the requwement. that test shall be repeated twice The results of both retests shall meet the requirement Spec*mens for the retest may be taken from the onnal test piece or from a new test piece. For chemical analysis, retest need only be for those spec*fic elements that failed to meet their test requwement. If the results of one or both retests fail to meet the requirement, the material under test shall be considered as not meeting the requirements of this spedfation for that classafcetlon.
In the event that, dunng preparation or after completion of any test. li is clearly determined that prescribed or proper procedures were not followed in prepanng the weld lest piece or test specimen(s), or In conducting the tests, the test shall be considered invalid, without regard to whether the test was actually completed, or whether the test results met, or failed to meet, the requirement. That lest shall be repeated, following proper proscribed procedures. In this case, the requirement for doubling the number of test pieces does not apply.
9 TechnIcal delivery conditions
Technical delivery conditions shall meet the requvements in ISO 544 and ISO 14344.