HENDRANATA, DENI (2025) ANALISIS UJI KETAHANAN KOROSI MATERIAL STRUKTUR RANGKA UTAMA SEPEDA MOTOR PADA DAERAH TROPIS PANTAI DAN INDUSTRI. S2 thesis, Universitas Mercu Buana Jakarta.
|
Text (HAL COVER)
01 COVER.pdf Download (563kB) | Preview |
|
![[img]](https://repository.mercubuana.ac.id/style/images/fileicons/text.png) |
Text (BAB I)
02 BAB 1.pdf Restricted to Registered users only Download (162kB) |
|
|
Text (BAB II)
03 BAB 2.pdf Restricted to Registered users only Download (478kB) |
|
|
Text (BAB III)
04 BAB 3.pdf Restricted to Registered users only Download (593kB) |
|
|
Text (BAB IV)
05 BAB 4.pdf Restricted to Registered users only Download (4MB) |
|
|
Text (BAB V)
06 BAB 5.pdf Restricted to Registered users only Download (117kB) |
|
|
Text (DAFTAR PUSTAKA)
07 DAFTAR PUSTAKA.pdf Restricted to Registered users only Download (119kB) |
|
|
Text (LAMPIRAN)
08 LAMPIRAN.pdf Restricted to Registered users only Download (2MB) |
Abstract
Structural corrosion in motor vehicles operating in tropical regions emerged as a critical issue in 2023, with structural failure posing significant risks to safety and material service life. High humidity and aggressive ions from coastal atmospheres and industrial activities accelerate the degradation of metallic materials, particularly those subjected to residual tensile stress. This study aims to evaluate the corrosion resistance of low-carbon steel type Steel Plate Hot Commercial Pickled and Oiled (SPHC PO) as a potential structural material, considering limited industrial access to High Strength Steel (HSS) specifications. Environmental exposure tests were conducted using simulated salt spray and artificial acid rain at pH 4.1–5.5 over durations of 96, 504, and 800 hours. Both uncoated and zinc phosphate-coated specimens were subjected to U-bent treatment to simulate residual tensile stress distribution. Surface morphology and elemental composition were characterized using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), while electrochemical behavior was interpreted through Pourbaix diagrams.Results indicate that uncoated SPHC PO exhibited high corrosion rates (0.46–1.08 mm/year), with the highest rate of 1.08533 mm/year under acid rain exposure at 800 hours, classified as poor to moderate, implying a service life of less than 3 years. In contrast, zinc phosphate coating significantly reduced corrosion rates to 0.06–0.08 mm/year, with the lowest values recorded at 0.00003 mm/year (NaCl) and 0.00086 mm/year (acid rain), corresponding to excellent performance (≥5 years service life). Deflection-induced stress (H-holder) in uncoated specimens (241.9 mm) resulted in a corrosion rate of 0.62531 mm/year, whereas coated specimens under identical deflection recorded only 0.04349 mm/year. SEM analysis revealed intergranular microcracks in uncoated samples, while coated specimens exhibited mild pitting and crystal fragmentation. EDS detected increased concentrations of carbon (69–72%) and oxygen (25– 27%) on coated surfaces due to contaminant adsorption. Pourbaix diagrams indicated coating dissolution zones at pH < 5 and Eh > 0.5 V. It is concluded that zinc phosphate-coated SPHC PO demonstrates viable corrosion and structural resistance as an alternative to HSS, with the recommendation of an additional top coat layer to ensure performance exceeding 5 years. Keywords: SPHC PO, Tropical Corrosion, Zinc Phosphate, Stress Corrosion Cracking, Salt Spray, Acid Rain, Pourbaix Diagram, SEM-EDS, Surface Protection, Residual Stress, U-bent Test, Material Service Life, Frame Design, Industrial Environment. Korosi struktural kendaraan bermotor di wilayah tropis menjadi isu kritis pada tahun 2023, patah struktur berdampak pada keselamatan dan masa pakai material. Kelembapan tinggi, dan ion agresif dari atmosfer pesisir dan aktivitas industri, mempercepat degradasi material logam yang mengalami tegangan residual. Penelitian ini bertujuan mengevaluasi ketahanan korosi baja karbon rendah tipe Steel Plate Hot Comercial Pickled and Oil (SPHC PO) sebagai alternatif material struktural, mengingat keterbatasan akses industri terhadap spesifikasi teknis High Strength Steel (HSS). Pengujian lingkungan dilakukan menggunakan simulasi kabut garam dan hujan asam buatan pada pH 4,1–5,5 selama 96, 504, dan 800 jam. Spesimen polos dan berlapis zinc phosphate (Coating) diberikan perlakuan U-bent untuk merepresentasikan distribusi tegangan tarik sisa. Karakterisasi morfologi dan komposisi permukaan dilakukan melalui Scanning Electron Microscope (SEM)-Energy Dispersive Spectoscope (EDS), dan perilaku elektrokimia diinterpretasikan menggunakan diagram Pourbaix. Hasilnya menunjukkan, SPHC PO tanpa Coating mengalami laju korosi tinggi (0,46–1,08 mm/tahun), nilai tertinggi 1,08533 mm/tahun pada hujan asam 800 jam, masuk kategori buruk–sedang, dan berimplikasi pada umur pakai <3 tahun. Sebaliknya, pelapisan zinc phosphate menurunkan laju korosi hingga –0,06–0,08 mm/tahun, dengan nilai terendah 0,00003 mm/tahun (NaCl) dan 0,00086 mm/tahun (hujan asam) pada durasi yang sama, masuk kategori sangat baik (umur pakai ≥5 tahun). Defleksi (H-holder) material polos (241,9 mm) menghasilkan laju korosi 0,62531 mm/tahun, sedangkan spesimen Coating dengan defleksi sama mencatat 0,04349 mm/tahun. SEM mengidentifikasi retakan mikro intergranular pada spesimen polos, sedangkan Coating menunjukkan pitting ringan dan fragmentasi kristal. EDS menunjukkan kenaikan unsur C (69–72%) dan O (25–27%) pada Coating akibat adsorpsi kontaminan. Diagram Pourbaix memperlihatkan zona pelarutan Coating saat pH < 5 dan Eh > 0,5 V. Disimpulkan bahwa SPHC PO berlapis zinc phosphate terbukti memiliki ketahanan korosi dan struktur yang layak sebagai alternatif HSS, dan disarankan tambahan lapisan top coat untuk performa ≥5 tahun. Kata Kunci: SPHC PO, Korosi Tropis, Zinc Phosphate, Stress Corrosion Cracking, Kabut Garam, Hujan Asam, Pourbaix Diagram, SEM-EDS, Baja Karbon Rendah, Perlindungan Permukaan, Tegangan Sisa, U-bent Test, Umur Pakai Material, Desain Rangka, Lingkungan Industri.
Actions (login required)
 |
View Item |
