PENGARUH LINGKUNGAN KOROSIF TERHADAP LAJU KOROSI PADA PIPA MINYAK DAN GAS

PENGARUH LINGKUNGAN KOROSIF TERHADAP LAJU KOROSIPADA
PIPA MINYAK DAN GAS
Oleh: Aulia Rahman ( 05510089 )
Electrical Engineering
Dibuat: 2008-02-23 , dengan 3 file(s).

Keywords: Lingkungan, tingkat korosi, pipa minyak dan gas
Abstraksi
Akhir-akhir ini sering terjadi kebocoran instalasi pipa minyak dan gas seperti kasus
kebocoran pipa lapindo disidoarjo 2006 lalu; kebocoran pipa minyak PT Midco E&T di Muara
EnimSumatra Selatan 10 Mei 2005; kebocoran pipa di Pembangkit Listrik Tenaga Gas dan Uap
Sicanang Belawan-Medan. Kebocoran tersebut bisa disebabkan banyak faktor yang
dikelompokan
atas faktor teknis (kesalahan manusianya) dan nonteknis (akibat faktor alam). Faktor teknis
misalnya
akibat kelalaian manusia dalam proses pengerjaan sehingga menyebabkan cacat pada instalasi
pipa
sehingga berpotensi pada kebocoran, dan nonteknis yaitu korosi.
Penyambungan logam dengan sistem pengelasan banyak digunakan. Pada pengelasan, biaya
murah, pelaksanaan relative lebih cepat, lebih ringan, dan bentuk konstruksi lebih variatif.
Sambungan

las juga memiliki kelemahan; timbulnya lonjakan tegangan yang besar disebabkan oleh
perubahan
struktur mikro pada daerah sekitar las yang menyebabkan turunnya kekuatan bahan dan akibat
adanya
tegangan sisa, serta adanya retak akibat dari proses pengelasan.
Berangkat dari kenyataan diatas, maka itu perlu penelitian lebih lanjut mengenai hal- hal tersebut
sehingga didapat dalil yang dapat dipertanggung jawabkan. Dan dapat dijadikan acuan dalam
proses
coating (pelapisan) atau perencanaan ketahanan korosi, karena penelitian ini merupakan
diagnosa
serangan korosi yang rentan terhadap spesimen
Metal join with weld system use often. In weldment, have save cost, relative ly fast work,
more light, and variety construct. Weldment have weakness is appear of strain that big cause of
differences microstructur on weld zone that metal strength down and cause residual stress, and
crack
cause weldment.
The point of this experience worked is want to know influence of corrosive environment that
give at corrosion rate in experiment specimen. And to know forms of exposure corrosion that
happen
from rate corrosion that result. Then to know micro corrosion that happen in specimen that weld

(weld

metal, heat affected zone, and base metal). Endly can be recommendation in coating process or
corrosion resistant plant because this experiment is diagnose corrosion attack that susceptible in
speciment.
In this experiment, have experiment methode, that each specimens group exposed in
environment that digerences is NaCl 10%, H 2 SO 4 10%, and moist environtment, until hour
168.
Then test measure rate corrosion, then test micro corrosion dan macro corrosion that happen as
influence environments its in speciment IRON API5L-X52 that weld.
The results, forms of corrosion that happen on specimen is in moist environment is uniform
corrosion that thin (corrosion rate = 0), on expose environment NaCl 10% liquid is uniform
corrosion
that thick and pitting corrosion (corrosion rate = 2,036 Mpy), then on expose environment
H2 SO 4 10% is happen uniform corrosion and pitting corrosion that more thick (corrosion rate =
53,041 Mpy).
Form of micro corrosion that happen is selective leaching corrosion (in Base Metal, Weld Metal,
and
Heat Affected Zone). Zone that more corrosion attack is HAZ (10,797 %) as result thermal strain
from

weld thermal influence, then BM zone (8,978 %) result oxidation on exposure cause lost of
shield
elements and on corrosion resitant reduce, then WM zone (5,94 %) is influence of weld process,
and
because chemistry property that more better in shield of corrosion and compensation from
residual
stress.