Failure in Fuel Injector Nozzles Used in Diesel Engines

Laser thermal hardening of steel (laser hardening) consists in heating a section of the steel surface above the phase transition temperature by laser radiation, followed by rapid cooling due to heat removal.As a result of this treatment, martensite is formed -a saturated solid carbon solution in -iron. For laser hardening, gas CO2 lasers, solid-state (mainly Nd:YAG) and fiber lasers with a power of 0.5 kW or more are most often used. Optical systems for deploying and scanning the beam allow you to harden large areas of the surface with maximum efficiency. Not all products need processing of significant areas. Measuring and cutting tools, parts of fuel equipment, pump injectors are subject to significant abrasive wear of individual small areas. Less powerful lasers can be used to process them. There are no results of using low power pulsed lasers (up to 20 W) for surface hardening of steel products. The purpose of this work is to determine the modes of surface hardening of parts and tools made of carbon and alloy steels using low power pulsed solid-state YAG lasers. For laser hardening, a solid-state YAG laser with a power of 5 W (diode pumping, radiation wavelength  1.064 m, pulsed mode) was used. The use of a nonlinear crystal made it possible to obtain UV radiation from   0.355 m (third harmonic). Processing with single pulses and multi-pulse processing with short pulses were investigated. Thermal hardening was carried out on carbon and alloy steels of various compositions: 20, 45, У12, Р6M5, Р9, ШХ15, structural and tool steels for the purpose. The possibility of hardening by UV radiation was evaluated on steels 20, 45, У12 and ЩХ15. The efficiency of laser thermal hardening was evaluated by measuring microhardness. For surface hardening of products, where partial melting of the surface is possible, low-power pulsed lasers can be used. Laser hardening by UV radiation is a promising direction for thermal hardening of steels without surface melting. Hardening with a low-power laser is expedient for hardening parts of fuel equipment.

show abstract

“…The best materials for spray needles are steel Р18 and steel Р9 [20]. At this work it was offered to use a needle made of steel Р9.…”

Section: Features Of Laser Hardening Of Parts Of Fuel Equipmentmentioning

confidence: 99%

New Technologies of Laser Hardening of Parts of Fuel Equipment

Hnatenko¹,

Afanasieva²,

Lalazarova³

et al. 2023

J. Nano- Electron. Phys.

View full text Add to dashboard Cite

show abstract

“…This is caused, among others, by forcing fuel through an injection pump at a pressure of up to about 250 to 300 MPa and its rapid changes in the high-pressure part of the fuel system as a result of fuel being injected into the engine's combustion chambers. Reaching so high pressures requires the manufacture and fitting of movable mating parts to very tight tolerances (often with an accuracy of 1 μm) [1][2][3][4][5][6]. With the precision being so high, those key components of high-pressure injection systems are very sensitive to any solid impurities or EN 590 non-conforming substances which can be found in fuel, leading to damage resulting in injection system malfunctioning and the need for usually very expensive repairs.…”

Section: Introductionmentioning

confidence: 99%

“…In practice, various types of impurities can be found in commercial fuels including the hard abrasive solid particles, soft particles, resinous (organic) substances, microbiological structures, water, etc. [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Examination of particulate contamination contents in commercial diesel fuel

Stępień

Żółty

2020

Finnish J. Trib.

View full text Add to dashboard Cite

The purity of diesel fuel is a crucial issue, in particular in the face of modern injection systems operating under very high pressures with very precisely fitted mating parts. At such pressures and in high temperatures, injectors are particularly exposed to abrasive wear due to the presence of fine, hard abrasive particles in diesel fuel. This article presents the results of diesel fuel contamination with abrasive particles in various size ranges (above 1, 2, 3, 4, 6 and 14 µm) determined in accordance with ASTM D7619 and EN 12662. Fuel samples came from leading manufacturers and were collected at filling stations which are the last links of the distribution chain. Furthermore, all diesel fuels were tested for compliance with all the requirements of EN 590. Analysing the results obtained, the problem of contamination with abrasive particles was found to be present in Poland. Around 37% of the samples tested did not meet the requirements of the Worldwide Fuel Charter (WWFC) in terms of purity class (ISO code 18/16/13 for particles in the range above 4, 6 and 14 µm according to ISO 4406). Violations of the purity class were found mainly for particles in the range over 4 µm. A very large number of particles from the lowest ranges, which are not included in the Worldwide Fuel Charter (above 1, 2 and 3 µm), were also found, and these may cause damage to fuel injection systems. The number of particles in the range above 1 μm in majority of samples exceeded the class 22, and that of those in the range above 2 and 3 μm was mainly between classes 19 and 21. Moreover, no correlation was found between the results of the particulate matter determination (ASTM D 7619) and the total impurity content (EN 12662). Based on the results of the tests carried out, it can be concluded that exceeded number of particles in individual size ranges are not always related to the content of impurities in a form of metallic pulp, impurities from outside the system or the precipitation of enriching additives. Nevertheless, they may be one of the factors contributing to damage to precision fuel injection systems.

show abstract

Problems of regeneration of modern piezoelectric fuel injectors

Stoeck¹

2022

Combustion Engines

View full text Add to dashboard Cite

The paper presents a method of testing piezoelectric fuel injectors in modern common rail systems, which allows them to be repaired almost to the full extent. The obtained results indicate that this process can be effectively carried out, even taking into account the existing technological limitations. The most important stages of the implemented activities are specified, first of all the scope of required maintenance activities in the pre- and post-assembly stages, as well as the types of diagnostic tests carried out on separate test benches. Although the presented analysis concerns a specific example, individual conclusions and observations can be applied to fuel injectors from other manufacturers, in which the actuator is not replaceable.

show abstract

Failure in Fuel Injector Nozzles Used in Diesel Engines

Cited by 4 publications

References 7 publications

New Technologies of Laser Hardening of Parts of Fuel Equipment

New Technologies of Laser Hardening of Parts of Fuel Equipment

Examination of particulate contamination contents in commercial diesel fuel

Problems of regeneration of modern piezoelectric fuel injectors

Contact Info

Product

Resources

About