Analisa Kegagalan Pegas Daun (Leaf Spring) Pada Mobil Mitshubishi L30

Trisna Iqbaldi, Wahyu (2022) Analisa Kegagalan Pegas Daun (Leaf Spring) Pada Mobil Mitshubishi L30. Other thesis, Universitas Islam Riau.

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Abstract

A leaf spring is a component in a car that functions to increase comfort for the driver. With the nature of an elastic spring, the spring functions to receive wheel vibration or shock due to the road conditions being traversed with the aim that the vibration or wheel does not transmit to the body. In reality on the ground, MITSHUBISHIL 300 cars often break or fail. This research was conducted aiming to find out the cause of the fracture or failure of the leaf spring steel by carrying out chemical composition tests, the result was that the used leaf springs experienced an increase in the carbon element which affected the material properties which further increased hardness and tensile strength but on the other hand the material will become brittle and decrease in ductility. Manganese element in used leaf spring steel has decreased which is very influential on the tensile strength of the material, tensile testing of new spring steel material obtained the mechanical properties of new leaf spring steel. (The new specimen has a yield strength of 1515 MPa, the ultimate strength of 1584 MPa is ductile fracture. The used specimen has a yield strength of 1149 MPa, the ultimate strength of 1367 MPa failed to experience brittle fracture. Observation of fractures where corrosion can be the initial cause of fatigue cracks. Then stress occurs in the bolt holes increasing the working stress. From the microstructural testing in the image results it can be seen that the leaf spring steel is close to the fracture area of the visible microstructure are ferrite (bright), pearlite (dark), martensite (needle). The perlite phase here is more dominant and the phase looks very tenuous and not dense and like mertensite (needle) which shows a fracture effect due to the hardening process.

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