A Review of Crack Initiation and Propagation Characteristics of Cast Steels: Trends for Enabling the Reliable Use of Steel Castings

Steel castings are used in a wide range of industries, but there is a general shortage of accessible data on both crack initiation and propagation characteristics pertinent to their design for fatigue applications. The present study reviews literature data on the initiation and propagation characteristics of cast steels and illustrates some useful trends for designing with steel castings. Crack propagation rate and threshold data are framed within guidelines from flaw assessment procedures, indicating that codified values offering reasonably conservative guidance for wrought and welded structures can also do so for steel castings. Crack initiation data for a range of carbon, low-alloy, and high-alloy steels are framed within life estimation methods developed predominantly from wrought steels, and a modification to a previously established regression relationship is proposed, resulting in largely reasonable life predictions for cast steels. The compatibility of the approach with a previously developed generalized fatigue assessment procedure is also illustrated, highlighting its potential to integrate within stress-based frameworks.