PD ISO/TR 23602:2005

Foreword
1 Scope
2 Normative references
3 Types of chain and extraction of specimens
4 Materials, chemical composition and heat-treatment
5 Tensile tests on chains
6 Conventional tensile tests on standard specimens
7 Notch impact tests
8 Fracture mechanics tests on notched chain links with slits
9 Fracture mechanics tests on notched three-point bend
   specimens with slits and fatigue cracks
10 Correlation between the load-bearing capacity of chain
   links containing slits and material toughness
11 Fracture mechanics derivation of chain links
12 Load-bearing and brittle fracture transition concept -
   Requirements
13 Correlation of test results with data from the literature
14 Summary
Bibliography

States an investigation to quantify the required material toughness for the operational safety of round steel chains.

The objective of the investigation presented in this Technical Report was to quantify the required material toughness for the operational safety of round steel chains. The determination of this toughness must take place under unfavourable boundary conditions, i.e. at the lowest permissible operating temperature on damaged (precracked) chains. On the basis of characteristic properties determined on chains and three-point bend (TPB) specimens and the notch impact energy, a load-bearing and brittle fracture transition temperature concept was elaborated. From the correlation of the fracture stress of chains, fracture mechanics characteristic properties and the notch impact energy, minimum values of the notch impact energy can be derived which yield adequate safety against fracture for the damaged chain. Furthermore, in order to exclude brittle failure of chains, the position of the lowest permissible operating temperature relative to the NDT (nil-ductility transition) temperature was determined. Finally, the linkage of the determined fracture mechanics properties to notch impact energy values and the definition of the requirements for these values furnishes a simple test and acceptance procedure for chain materials and chain types.