TY  - GEN
CY  - UNIVERSITAS LAMPUNG
ID  - eprints83706
UR  - http://digilib.unila.ac.id/83706/
A1  - TRI , KUSUMA WARDANI
Y1  - 2024/05/28/
N2  - Pipa baja API 5L Grade B merupakan pipa yang digunakan dalam
transportasi minyak bumi dan gas alam. Tujuan dari penelitian ini adalah
untuk mengetahui karakteristik perambatan retak fatik pada material pipa
baja API 5L-B. Uji tarik (ASTM 8) dan uji perambatan retak fatik (ASTM
E647) menggunakan spesimen Compact Tension (CT). Parameter pengujian
yang digunakan dalam penelitian ini yaitu Pmax = 3,566 kN, Pmin = 0,357 kN,
?yield = 399.251 MPa dan f = 10 Hz. Pengukuran panjang retak
menggunakan metode compliance serta data panjang retak dan jumlah siklus
dianalisis menggunakan metode polynomial incremental untuk menentukan
laju perambatan retak fatik (da/dN) dan faktor intensitas tegangan (?K).
Plot data da/dN vs ?K dilakukan untuk menentukan koefisien persamaan
Paris pada daerah perambatan retak stabil-stage II. Nilai konstanta m =
3,607 dan nilai konstanta C = 1,176x10-12

. Pengamatan mikrostruktur
material menggunakan mikroskop optik menunjukkan fasa ferit dan perlit.
Pengamatan SEM pada permukaan patahan menunjukkan pola patahan
intergranular. Selain itu, permukaan patahan menunjukkan adanya garis
striasi, secondary crack dan voids.

Kata Kunci : Pipa baja API 5L grade B, Perambatan retak fatik,

Mikrostruktur, Fraktografi

iv

ABSTRACT

FATIGUE CRACK PROPAGATION CHARACTERISTICS OF TYPE API 5L

PSL -1 GRADE B STEEL PIPE

By

TRI KUSUMA WARDANI

API 5L Grade B steel pipe is a pipe used in the transportation of petroleum
and natural gas. The purpose of this study is to determine the characteristics
of fatigue crack propagation in API 5L-B steel pipe material. Tensile test
(ASTM 8) and fatigue crack propagation test (ASTM E647) using Compact
Tension (CT) specimens. The parameters used during the test were Pmax =
3,566 kN, Pmin = 0,357 kN, ?yield = 399.251 MPa and f = 10 Hz. Crack
length measurements using the compliance method and data on crack length
and number of cycles were analyzed using the incremental polynomial
method to determine the fatigue crack propagation rate (da/dN) and stress
intensity factor (?K). A plot of da/dN vs ?K data was performed to
determine the coefficients of the Paris equation in the stable-stage II crack
propagation region. The constant value m = 3,607 and the constant value
C = 1,176x10-12

. Microstructural observations of the material using optical
microscopy showed ferrite and pearlite phases. SEM observation of the
fracture surface showed an intergranular fracture pattern. In addition, the
fracture surface showed the presence of striation lines, secondary cracks
and voids.

Key words : API 5L grade B steel pipe, Fatigue crack propagation,

Microstructure, Fractograf
PB  - FAKULTAS TEKNIK
TI  - KARAKTERISTIK PERAMBATAN RETAK FATIK PIPA BAJA TYPE

API 5L PSL -1 GRADE B

AV  - restricted
ER  -