DIN EN 1561:1997 Grey Cast Iron
Grey cast iron is casting alloy, iron and carbon based, the latter element being present mainly in the form of lamellar graphite particles.
The properties of grey cast iron depend on the form distribution of the graphite and the structure of the matrix
This European standard deals with the classification of grey cast iron accordance with the mechanical properties of the material, either tensile strength hardness.
1. Scope
This standard specifies the properties of unalloyed and low alloyed grey cast iron used for castings, which have been manufactured in sand moulds with comparable thermal behavior.
This standard specifies the characterizing properties of grey cast iron by
Tensile strength of separately cast samples, or if agreed by manufacturer and the purchaser by the time of acceptance of the order, of cast-on samples or samples cut from casting
If agreed by the manufacturer and the purchaser by the time of acceptance of the order, the hardness of the material measured on castings or on cast-on knob
This standard does not apply to grey cast iron used for pipes and fittings according to EN 877-1.
This standard specifies six grey cast irons according to the tensile strength and six grey cast irons according to the brinell hardness
2. Definitions
2.1 Grey Cast iron
Iron-carbon material in which the free carbon is present as graphite, mainly in lamellar form
2.2 Relative hardness
Quotient of measured hardness to the hardness calculated from the measured tensile strength by means of an empirical relationship
2.3 Relevant wall thickness
Wall thickness for which the mechanical properties apply
Note : The relevant wall thickness is twice the modulus or twice the volume/surface ratio
3. Manufacture
The method of manufacturing of grey cast iron and its chemical composition shall be left to the discretion of the manufacturer, who shall ensure that the requirements defined in this standard are met for the material grade specified in the order
4. Requirements
4.1 Tensile properties
Grey cast iron is casting alloy, iron and carbon based, the latter element being present mainly in the form of lamellar graphite particles.
The properties of grey cast iron depend on the form distribution of the graphite and the structure of the matrix
This European standard deals with the classification of grey cast iron accordance with the mechanical properties of the material, either tensile strength hardness.
1. Scope
This standard specifies the properties of unalloyed and low alloyed grey cast iron used for castings, which have been manufactured in sand moulds with comparable thermal behavior.
This standard specifies the characterizing properties of grey cast iron by
Tensile strength of separately cast samples, or if agreed by manufacturer and the purchaser by the time of acceptance of the order, of cast-on samples or samples cut from casting
If agreed by the manufacturer and the purchaser by the time of acceptance of the order, the hardness of the material measured on castings or on cast-on knob
This standard does not apply to grey cast iron used for pipes and fittings according to EN 877-1.
This standard specifies six grey cast irons according to the tensile strength and six grey cast irons according to the brinell hardness
2. Definitions
2.1 Grey Cast iron
Iron-carbon material in which the free carbon is present as graphite, mainly in lamellar form
2.2 Relative hardness
Quotient of measured hardness to the hardness calculated from the measured tensile strength by means of an empirical relationship
2.3 Relevant wall thickness
Wall thickness for which the mechanical properties apply
Note : The relevant wall thickness is twice the modulus or twice the volume/surface ratio
3. Manufacture
The method of manufacturing of grey cast iron and its chemical composition shall be left to the discretion of the manufacturer, who shall ensure that the requirements defined in this standard are met for the material grade specified in the order
4. Requirements
4.1 Tensile properties
Table 1
(1) If cast-on sample is to be used the relevant wall thickness of the casting shall be agreed upon by the time of acceptance of the order
(2) If by the time of acceptance of the order proving of the tensile strength has been agreed, the type of the sample is also to be stated on the order. If this is lack of agreement type of sample is left to the discretion of the manufacturer
(3) For the purpose of acceptance the tensile strength of a given grade shall be between its nominal value n (position 5 of the material symbol) and (n+100) N/mm2.
(4) This column gives guidance to the likely variation in tensile strength for different casting wall thickness when a casting of simple shape and uniform wall thickness is cast in a given gray cast iron material. For castings of non-uniform wall thickness or castings containing cored holes, the table values are only an approximate guide to the likely strength in different sections, and casting design should be based on the measured tensile strength in critical parts of the casting.
(5) These values are guide-line values. They are not mandatory
(6) This value is included as the lower limit of the relevant wall thickness range
(7) The values relate to samples with an as-cast casting diameter of 30 mm, this corresponds to a relevant wall thickness 0f 15 mm
4.2 Hardness properties
If it is not possible to use the Brinell test method (EN 1003-1), alternative test methods may be used, which shall have correlated values with Brinell test.If a casting is ordered on the basis of hardness, the relevant wall thickness and the position of the test shall be agreed upon by the time of the acceptance of the order
Table 2
(2) If by the time of acceptance of the order proving of the tensile strength has been agreed, the type of the sample is also to be stated on the order. If this is lack of agreement type of sample is left to the discretion of the manufacturer
(3) For the purpose of acceptance the tensile strength of a given grade shall be between its nominal value n (position 5 of the material symbol) and (n+100) N/mm2.
(4) This column gives guidance to the likely variation in tensile strength for different casting wall thickness when a casting of simple shape and uniform wall thickness is cast in a given gray cast iron material. For castings of non-uniform wall thickness or castings containing cored holes, the table values are only an approximate guide to the likely strength in different sections, and casting design should be based on the measured tensile strength in critical parts of the casting.
(5) These values are guide-line values. They are not mandatory
(6) This value is included as the lower limit of the relevant wall thickness range
(7) The values relate to samples with an as-cast casting diameter of 30 mm, this corresponds to a relevant wall thickness 0f 15 mm
4.2 Hardness properties
If it is not possible to use the Brinell test method (EN 1003-1), alternative test methods may be used, which shall have correlated values with Brinell test.If a casting is ordered on the basis of hardness, the relevant wall thickness and the position of the test shall be agreed upon by the time of the acceptance of the order
Table 2
(1) For each grade, Brinell Hardness decreases with increasing wall thickness
(2) By agreement between the manufacturer and the purchaser a narrower hardness range maybe adopted at agreed position on the casting, provided that this is not less than 40 Brinell Hardness units. An example of such a circumstance could be castings for long series production
(2) By agreement between the manufacturer and the purchaser a narrower hardness range maybe adopted at agreed position on the casting, provided that this is not less than 40 Brinell Hardness units. An example of such a circumstance could be castings for long series production
5 Sampling
5.1 Tensile test
5.1.1 Separately cast samples
The separately cast samples to establish the material grade shall be cast vertically. The moulds shall be either sand moulds or moulds with comparable thermal diffusivity. The moulds may be made for casting several samples simultaneously.
5.1 Tensile test
5.1.1 Separately cast samples
The separately cast samples to establish the material grade shall be cast vertically. The moulds shall be either sand moulds or moulds with comparable thermal diffusivity. The moulds may be made for casting several samples simultaneously.
All dimensions are given in milimeters
The Length (L) shall be determined according to the length of the test piece and clamping divice used. Other dimensions of the mold should meet the dimensional requirements.
Samples of other dimensions and using other casting procedures may be agreed between the manufacturer and the purchaser for the purpose of representing the properties of particular castings.
Samples shall be made from the metal used to produce the castings which they represent and during the same period was when the castings are made.
The frequency of casting the separately cast samples shall be in accordance with the in-process quality assurance procedures adopted by the manufacture.
The sampels shall be stripped from the mould at temperature not exceeding 500 C.
5.1.2 Cast-on Samples
The test pices used for the tests shall be machined from a cast-on sample. The type of sample shall be chosen in such a way as to provide approximately the same cooling conditions as for the casting to be represented. The type of sample and the location of the sample on the casting shall be agreed between the manufacturer and the purchaser. If there is no such agreement, the manufacturer shall decide on the type of sample and it shall be located at a representative position on the casting.
* The small size set is used for casting less than 80mm thickness and the large size set is used for castings equal to or greater than 80 mm wall thickness
* Cast-on samples should only be used when casting is more than 20 mm thickness and th nass is more than 200 kg
5.1.3 Test Piece cut from a casting
All dimensions are in millimeters
Table 1 shows anticipated minimum values of tensile strength for test pieces cut from a casting with uniform section of sample shape
* Values obtained in castings of variable wall thickness can differ from those given in table 1
5.2 Hardness Test
Hardness test may be carried out on the separately cast samples
Alternatively, the brinell hardness test may be carried out, by agreement between the manufacturer and the purchaser, on a test piece ("Brinell knob") which is cast on to the casting as shown bellow. The position of the brinell knob. and its size and shape, shall be agreed between the manufacturer and purchaser by the time of acceptance of the order.
In order to carry out the brinell hardness test, the test piece is removed from the casting, ground on the cut surface and then tested on the ground surface
6. Test Method
6.1 Tensile test
The tensile test shall be carried out in accordance with the requirements of EN 1002-1. The dimensions of the test piece shall conform to the dimensions given in table 3. The gripped parts may be either threaded or plain to suit clamping device
