THE DESIGN OF WEAR AND TEAR ON SHIP AN ALTERNATIVE MATERIALS IN PLACE OF TAIL SHAFT
2. MATERIALS AND METHODOLOGY
2.1. Shaft
The shaft line alignment consists of determining the location of the main engine driving axis, intermediate bearing axis. Propeller shaft has a function as the main mechanical power from the main engine to the propeller so that it can generate thrust on the ship. In general the propeller shaft is divided into 3 parts namely : thrust shaft, intermediate shaft and tail shaft. (Boddapati et al., 2015)
2.2. Heat Treatment
Heat treatments procedure chosen include:
annealing, normalizing, quenching and tempering after water quenching. Annealing, normalizing and quenching are the most important heat treatments often used to modify the mechanical properties of
Indonesian Naval Technology College, STTAL Postgraduate International Conference, Vol. 2 ICMST 2018 July, 26th 2018
82 engineering materials particularly steels (Tanwer, 2014).
2.3. Hardness Measurements
The hardness of the untreated and post- treated welded samples was evaluated using a Vickers Hardness (LECO AT700 Microhardness Tester). Brinnel hardness testing aims to determine the hardness of a material resistance to the indentor that is emphasized on the surface of the test material (Arasu et al., 2013). Brinell hardness testing using a steel ball with a diameter of 10.
2.4. Tensile Testing
Tensile testing conducted to determine the yield point force, yield point stress, max force, max stress (ultimate tensile strength), max strain (break elongation), break force, reduction of area, strain, and modulus young). (Momoh et al., 2013)
2.4.1. Reduction of Area
Reduction of area that is in the area broken will happen reduction of cross-sectional area (Ghazi
& Mashloosh, 2015). Where the percentage of the reduction of cross-sectional area can be formulated as follows :
ROA = 𝐴𝑜−𝐴1
𝐴𝑜 𝑥 100% (1)
Where :
A0 = First cross-sectional area (mm2)
A1 = Cross-sectional area after tensile test (mm2)
2.4.2. Strain
Strain that is on the broken area will be an extension of material. Strain can be calculated by the following formula:
(2)
Where :
𝜀 = strain (%)
L1 = the length of the end of the test rod (mm) L0 = the initial length of the test material (mm)
2.4.3. Modulus young
Elastic modulus is required for calculating the elasticity of the test material and its non-fixed properties. The magnitude of elastic modulus can be calculated by the following formula:
(3) Where :
𝜎 = ultimate tensile strength (Kg/mm2, psi, MPa)
E = Strain (%) 2.5. Bending Test
Figure obtained after implemented bending test, when the maximum load fiven can be seen visually is material test bent or broken when pressed by tool. To find the curve stress can be calculated by the following formula:
(4)
Where :
P = Maximum load acceptable for test material L = Length of material support
d = The diameter of the material test 2.6. Impact Test
To find the Impact value can be calculated by the following formula:
(5)
Where :
HI = Impact Value m = mass pendulum g = gravity
R = Length of pendulum arm
A = Cross-sectional area material under the impact
2.7. Micro Test
Indonesian Naval Technology College, STTAL Postgraduate International Conference, Vol. 2 ICMST 2018 July, 26th 2018
83 The microstructures were then examined using metallurgical microscope Model- Axio at magnification of 100xx. (Seidu & Kutelu, 2013).
Micro testing is the examination of the material by looking at the surface structure of the etching section which has been etched with 400 time magnification (Sharma et al., 2013). In this test will be known the existence of material crack.
2.8. Testing the chemical composition
Testing the chemical composition conducted to determine the content of any existing in each material and to be used as a comparism one of the
material. And if these materials given the heat treatment is the chemical composition of the material will be changed or remain.
2.9. Research Methods
This research display data from secondary data of the material wear out. As well as the primary data the research is the material in doing test The next two data will be compared so it can be found the results. The first step is the identification of a problem, book study, data validation, data analysis, and withdrawal conclusion.
Fig. 2 Flowchart diagram of research
2.10. Analysis of Variance (ANOVA)
In this research, the data processing is done by comparing the data of tensile test and then compare the value of ultimate tensile strength (UTS), curve stress, impact, and hardness.
Data analyzing using ANOVA, is needed as a first steep to be able to see the difference value of each material variation test the following is an observation table with a single factor data analysis
process (one way anova) software IBM SPSS Statistics v16.
With assumption:
a. If Fcount < Ftable, then Ho accepted and H1
rejected, which means the variation of the test material after material preparation process can not affect the mechanical properties of the material.
Indonesian Naval Technology College, STTAL Postgraduate International Conference, Vol. 2 ICMST 2018 July, 26th 2018
84 b. If Fcount > Ftable, then Ho rejected dan H1
accepted, which means the variation of the test material after the material preparation process can affect the mechanical properties of the material.
2.11. Experimental calculation of test specimens
a. Data collection.
The data supporting both primary and secondary data, used to compile this research are as follows:
Primary data
Data research conducted by doing procedure, varying the material aalternative and the test one of the material is given heat treatment on material 4140.
Secondary data
Data test result material wear out used as a reference and comparism in the selection of material to be tested, Reference and theory Associated with this research can be obtained through journals, books, and others.
b. Data specimens
Specimens used in this research the material based on the type of material, composition of the material and tensile strength of these materials. As for the material obtained: the HQ 705 from PT. Tira Austenit Surabaya while the other material that is: 4340 dan 4140 from PT. Assab Surabaya.
c. Equipment used.
Equipment used to research, among others testing machine tensile, teting machine bend, test equipment impact, test equipment hardness, test equipment micro, testing machine composition, testing machine metallography, lathe, grinding, miserly, calipers, glasses and gloves.
d. Planning.
e. Testing Phase.