BS ISO 17804:2020

What is ISO 17804 about?

ISO 17804 defines the grades and the corresponding requirements for ausferritic spheroidal graphite cast irons.

ISO 17804 specifies five grades of ausferritic spheroidal graphite cast iron by a classification based on mechanical properties determined on machined test pieces prepared from:

• Separately cast samples, side-by-side cast, or cast-on samples
• Samples cut from a casting

ISO 17804 also specifies two grades by classification as a function of hardness.

Who is ISO 17804 for?

ISO 17804 on ausferritic spheroidal graphite cast irons is relevant to:

• Mining, earthmoving, and manufacturing industries
• Suppliers of graphite

Why should you use ISO 17804?

Ausferritic spheroidal graphite cast iron is a cast alloy, iron, carbon, and silicon-based, carbon primarily in the form of spheroidal graphite particles.

ISO 17804 deals with the classification of ausferritic spheroidal graphite cast irons in accordance with the mechanical properties of the material. The mechanical properties of these ausferritic spheroidal graphite cast irons depend on their structure, e.g., the form of the graphite and the structure of the matrix.

The mechanical properties of the material can be evaluated on machined test pieces prepared from:

• Separately cast samples with an appropriate gating system, able to provide metallurgical conditions like those of the castings they represent
• Samples cast in the mould alongside the casting, with a joint running system, hereafter called “side-by-side cast samples”
• Samples cast onto either the casting or the running system, hereafter referred to as “cast-on samples”
• Samples cut from a casting (only by agreement between the manufacturer and the purchaser, the agreement specifying the conditions of sampling and the values to be obtained)

ISO 17804 specifies two grades of ausferritic spheroidal graphite cast iron in an accordance with their hardness. These cast irons are used in applications where high abrasion resistance is required (e.g., mining, earthmoving, and manufacturing industries). ISO 17804 also specifies five grades of ausferritic spheroidal graphite cast iron by their mechanical properties.

When, for these grades, hardness is a requirement for the application, ISO 17804 provides the means for determining appropriate hardness ranges. Some ausferritic spheroidal graphite cast iron grades can be used for pressure equipment.

Overall, ISO 17804 is useful as the property values of these materials apply to castings cast in sand moulds or moulds of comparable thermal behaviour. The material designation is based on the minimum mechanical properties obtained in separately cast, cast side-by-side or cast-on samples.

What’s changed since the last update?

BS ISO 17804:2020 supersedes BS ISO 17804:2005, which is withdrawn.

BS ISO 17804:2020 replaces the first edition (ISO 17804:2005), which has been technically revised. The main changes compared with the previous edition are as follows:

• The normative references have been updated
• The terms and definitions have been improved and supplemented
• A side-by-side cast sample has been included
• The method of manufacturing has been made more detailed (including pouring/heat treatment)
• A subclause for graphite structure examination has been added