The Gasket Die Laser Hardening project aimed to enhance the wear resistance of gasket dies used in plate heat exchanger’s sealing gaskets production. Utilizing laser beam technology, we navigated the challenge of hardening the edges for improved durability without compromising ductility. Extensive experiments, guided by optimal parameters, successfully increased the hardness of the die’s narrow edges, promising a doubled lifespan. This innovative approach, avoiding the need for post-machining, signifies a significant advancement in local surface hardening for steel components. The project underscores our commitment to precision engineering and advanced manufacturing techniques in optimizing laser materials processing methods.

Research Highlights
- Successfully increased the hardness of vulnerable areas in a gasket die, foreseeing a twofold improvement in its lifespan.
- Achieved localized surface hardening on a steel part without the necessity for post-machining and additional post-processing steps, demonstrating the efficiency of the laser hardening process.
Challenges
In the Gasket Die Laser Hardening project, gasket dies crucial for the mass production of plate heat exchangers’ gaskets faced wear issues due to the movement of the die’s plates and the hot polymer material within. While hardening the die edges could reduce wear and enhance gasket quality, the ductility of the base metal was crucial. Conventional hardening methods were unsuitable as they increased the entire part’s hardness. The project focused on using a laser beam to selectively increase edge hardness without compromising base metal ductility. The key challenge was determining optimal laser hardening parameters to achieve enhanced wear properties without risking edge melting and detrimental changes to die geometry.
Our Solution
The optimal parameters for laser hardening of steel were determined through a comprehensive review of literature and extensive trial and error processes, specifically tailored for gasket die’s edges as thin as 0.2 mm as illustrated in Figure 2. Gasket die narrow sealing edges and its sensitive geometry.. Utilizing AISI 4140 steel for the gasket die material was chosen for its exceptional strength and ductility. Employing a heat treatment with high cooling rates would transform the microstructure of this alloy into martensite, significantly enhancing its hardness. However, caution was necessary to avoid excessive heat input during laser hardening. High laser powers and low traversing speeds risked melting the narrow edges of the die and potentially leading to undesirable changes in part geometry.

Numerous laser hardening experiments were executed on the steel base metal, incorporating various parameters. The resulting microstructure and micro-hardness were thoroughly investigated, with a representative example showcased in Figure 3.

Ultimately, the identified optimal parameters were implemented on the primary narrow edges of the gasket die, as illustrated in Figure 4. This application led to a notable increase in die hardness, elevating it from 250 HV to 620 HV, as depicted in Figure 3. This enhancement is anticipated to result in a twofold improvement in the wear properties.

Outcomes
- Successful implementation of gasket die laser hardening resulted in a notable threefold increase in the hardness of the narrow edges.
- This significant enhancement in hardness is anticipated to lead to a twofold improvement in the overall lifespan of the gasket dies, contributing to prolonged and improved performance.