# The Influence of Laser Shock Peening on the Microstructure and Mechanical Properties of AH32 Steel

## TL;DR

Laser shock peening improves the mechanical properties and wear resistance of AH32 steel used in shipbuilding.

## Contribution

The study demonstrates how laser shock peening enhances the microstructure and performance of AH32 steel.

## Key findings

- Laser shock peening introduces a high residual compressive stress of −162 MPa on AH32 steel surfaces.
- Surface hardness increased by 7.3% and 14.7% for two LSP-treated samples.
- LSP-treated samples showed improved elongation and reduced wear rates by over 40%.

## Abstract

The mechanical integrity of shipbuilding steel under demanding maritime service conditions is a pivotal factor for ensuring the structural safety and operational longevity of vessels. This research employs laser shock peening (LSP) to augment the surface performance of AH32 steel and carries out a comprehensive analysis of the influence and underlying mechanisms of LSP on both the microstructural evolution and mechanical properties of the material. The results indicate that the LSP treatment successfully introduced a high magnitude residual compressive stress (−162 MPa) at the surface of AH32 steel. Additionally, the surface hardness of LSP-1 and LSP-2 increased by 7.3% and 14.7%, respectively. The tensile test results indicate that Sample LSP-2 achieved a 25.8% improvement in elongation while exhibiting only a 5.9% reduction in ultimate tensile strength. Friction and wear tests demonstrated that the average coefficient of friction for the samples treated with LSP decreased by approximately 18%, while the wear rate reduced significantly by over 40%.