# Characterization of AISI 304 stainless steel based on laser cutting process optimization

## TL;DR

This study examines how laser cutting parameters affect the quality of cuts in stainless steel, finding that higher speeds and optimal focus improve surface smoothness and precision.

## Contribution

The study provides empirical data on the effects of cutting speed and focus position on surface roughness, kerf geometry, and microhardness in laser cutting of AISI 304 stainless steel.

## Key findings

- Surface roughness decreased from 5.4 µm to 4.0 µm as cutting speed increased from 1.5 to 3.5 m/min with optimal focus.
- Kerf width narrowed from 185 µm to 138 µm with higher cutting speed and optimal focus settings.
- Microhardness peaked at 270 HV under specific speed and focus conditions, indicating favorable thermal effects.

## Abstract

This study investigates the impact of cutting speed and laser focus position on surface roughness, kerf geometry, and microhardness during fiber laser cutting of 4 mm-thick AISI 304 stainless steel sheet. A series of experimental trials were conducted using fiber laser cutting with cutting speeds ranging from 1.5 to 3.5 m/min and focus settings between 30 and 50%, at fixed power of 2000 W and gas pressure equals 14 bar. Surface roughness (Ra) was found to decrease with increasing cutting speed; the highest Ra value recorded was 5.4 µm at 1.5 m/min and 40% focus, while the lowest value was approximately 4.0 µm at 3.5 m/min and 50% focus. Kerf width similarly decreased with increasing speed and optimal focus, narrowing from 185 µm at 1.5 m/min and 30% focus to as low as 138 µm at 3.5 m/min and 50% focus. Microhardness varied non-linearly, reaching a peak of 270 HV at 2.0 m/min and 30% focus, indicating favorable thermal gradients. SEM, EDS, and XRD analysis validated the outcomes indicative of a balanced performance across all evaluated parameters. These findings guide laser cutting optimization for improved precision and mechanical performance in stainless steel.