BS ISO 4991:2015 pdf download – Steel castings for pressure purposes
This International Standard covers steel castings for pressure containing parts.
lt includes materials which are used for the manufacture of components subject to pressure vesselcodes and components not subject to codes.
This International Standard relates to castings manufactured from unalloyed and alloyed steel grades(characterized by their chemical composition, Table 1, and mechanical properties,Tables 2, 3,4 and 5).NOTE Annex D gives information on ISo grade designation and available UNS numbers which are similar tothe lS0 grade designation.
The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its application.For dated references,only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies.
ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 4885, Ferrous products — Heat treatments — Vocabulary
ISO 4990, Steel castings —General technical delivery requirements
IS0 6892-1,Metallic materials —Tensile testing — Part 1: Method of test at room temperatureIS0 6892-2,Metallic materials —Tensile testing —Part 2: Method of test at elevated temperatureIS0 11970, Specification and approval of welding procedures for production welding of steel castingsISO 13520, Determination of ferrite content in austenitic stainless steel castings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4885 and IS0 4990 apply.
4Information to be supplied by the purchaser
Materials specified in this International Standard shall conform to the applicable requirements ofISO 4990 including the supplementary requirements listed inAnnex A that are indicated in the enquiryand purchase order.
The type of heat treatment shall comply with Table 6 for the specified grades.The temperatures givenare for information only.
When a grade may be delivered at different strength levels depending on the type of heat treatment (seeTable 2) the purchaser shall state at the time of enquiry and order the type of heat treatment required.The symbols for the type of heat treatment are as follows:
+QT quenched and tempered
+AT solution annealed
NOTE For definitions, see ISO 4885.
Welding is permitted, unless otherwise agreed. All the welds shall conform to the same criteria for non-destructive testing as the relevant part of the casting. Welding shall be carried out in accordance with ISO 11970.
The welding conditions are given in Annex B.
7.1 Chemical composition
An analysis of each heat shall be made by the manufacturer to determine the contents of the specified elements.
The chemical composition shall comply with the values given in Table 1.
Permissible deviations for the product analysis are indicated in ISO 4990.
7.2 Mechanical properties
The mechanical properties shall comply with the values given in Tables 2, 3, 4 and 5.
Mechanical properties shall be measured on test pieces taken from test blocks (according to ISO 4990).
The tensile tests at room temperature shall be carried out according to ISO 6892-1 and, if specified,impact tests according to ISO 148-1.
If required by agreement at the time of enquiry and order, impact energy properties at low temperature shall comply with Table 3.
If required by agreement at the time of enquiry and order, impact energy values at room temperature shall comply with Table 4.
If required by agreement at the time of enquiry and order, verification of the elevated temperature proof stress values shall be carried out at elevated temperatures in accordance with ISO 6892-2. In such a case, the values shall comply with Table 5.
Creep resistance mean values are given for information, for some grades in Annex C.
8 Inspection and testing
For all products ordered to the requirements of this International Standard, specific inspection and testing is required.
Test blocks shall be heat treated in production furnaces to the same procedure as the castings they represent.
Test pieces shall not be cut from the test block until the latter has been heat treated.
8.3 Formation of test lots
The formation of test lots shall be carried out in accordance with ISO 4990.
8.4 Non-destructive testing
The following information shall be given at the time of enquiry and order in accordance with ISO 4990:
— non-destructive methods required,
— area to be examined,
— acceptance criteria required.BS ISO 4991 pdf download.