Abstract Hardfacing is commonly applied to the working surfaces of demolition shears manufactured from high-strength steel base materials. These components are subjected to substantial dynamic loading, which fundamentally influences their service life. However, such base materials typically require preheating prior to hardfacing to mitigate the formation of brittle martensite during cooling. This preheating process is technically demanding and entails additional production costs. This study examines the effect of preheating on the microstructure, hardness, and impact behavior of quenched and tempered (Q + T) high-strength steels (S690QL, S960QL, S1100QL) used as base materials for hardfacing in demolition shears operating under dynamic loads. Hardness mapping across the heat-affected zones revealed that the influence of preheating diminishes with increasing base material strength: S690QL showed significant hardening differences, S960QL moderate, and S1100QL minimal. SEM analyses confirmed that microstructural variations between preheated and non-preheated conditions were negligible. Instrumented Charpy impact tests demonstrated that preheating slightly increased impact force and energy in lower-strength steels, while its effect was marginal for higher-strength grades.
Terdik et al. (2026) studied this question.