Coating of Oil Pipes Products with Erosion-Resistant Composite Materials Reinforced with Carbonates and Natural Wastes

Polymer based components are exposed to many damage influences during their lifetime. One of these influences erosion, which is a crucial problem in many industrial applications such as pipes, boats, sewage...etc. Due to impingements of solid particles being suspended in the fluids flowing at high velocity. This work reports an investigation of erosion wear characteristics and their resistance to erosion wear after coated by using (spin coating) with rice husk ash – mixed (epoxy resin). Composites specimens have been prepared by (Hand lay-up) molding method. The composite specimens are composed of epoxy resin as the matrix, and 6% vf of glass fiber as reinforcing material and filler powders from natural wastes and industrial processed powders at 3% and 6% vf. The natural wastes are rice husk ash (RHA), carrot waste and sawdust (wood powder) while industrial processed powders are Na2CO3, CaCO3 and K2CO3. Solid particles erosion wear tests and coating after erosion are also carried out. The coating specimens with RHA-mixed epoxy resin at an optimized size of the particles 1.4-4.2 μm improvement erosion wear resistance. The optical microscope results of the coated specimens show those coatings are resistant to erosion parameters.

No.25- (12) 2019 Journal of Petroleum Research & Studies (JPR&S) E43 source. The fiber waste was dried in the air and then grinding by using a grinder then sieved to obtain fine and coarse fiber [12 &13].

B. Rice Husk Ash Filler:
Filler rice-husk include about (50% cellulose), (25-30% lignin), and (15-20% of silica) [13]. First step the cellulose and lignin are extracted at burning, but dismissed behind silica ash. The environment of burning and temperature affect the particle size and a specific surface area of rice husk ash [14 &15]. To provide the greatest pozzolanas, the burning of the rice husk requirement accurately managed to maintain the heat under 700°C and to assure that the production of carbon is retained to a least by providing a sufficient amount of air. At temperatures below 700°C amorphous silica is created, which that less reactive, while at the temperatures above 700°C crystalline silica is created, which that more reactive, the second step was milling the RHA by using a grinder to obtain a fine powder [16].

C. Wood Fiiler (Sawdust):
Wood powder is a product of cut, milling, drill, sand, or on the other hand crushing wood with a saw or other tool formed of the finest wood particle, also the product by several animals, birds, and insects which live in wood, like the woodpecker and builder ant which that can perform a risk in construction industries, particularly in terms of its flammability [17].

A. Erosion Wear:
The consequence of erosion wear for the pure epoxy and (natural, industrial) composites is illustrated in tables 3&4 and figures 2&3. Particle collisions with the specimen surface lead to an increase in the temperature and this causes the material to easily distort the matrix (resin) [18]. Thus, this deformation causes the formation of a hole and loss of weight in the specimens [19]. Results show, the natural and industrial composites give the lower erosion wear when they are compared with the other patterns (pure EP. and EP. +6% G.F) composite. The reason is that the presence of reinforcement  E44 and filler in the matrix (resin) assistance in employing dynamic power produced through impacted particles erodent, therefore making the power possible of the flexible deformation of the matrix (resin) to become smaller, this agrees with [19]. The improvement of erosion resistance in specimens supported with fibers and natural powders can be attributed to advancement the hard surface of these specimens with addendum of this reinforcement and the imbibition of a perfect amount of kinetic energy correlated with erosive by filler. From tables 3&4 and figures 2&3 it is clear that there is a pronounced effect of the addition of 6% glass fiber with 3% volume fraction from (natural and industrial powder) on the erosion wear, it is reported that specimens (epoxy +6% glass fiber +3%, 6% RHA, CaCO 3 ) give greater erosive wear strength than specimens reinforced with (3%,6% carrot sawdust, Na 2 CO 3 , K 2 CO 3 ) because RHA has a high hardness value with small particle size and water absorption. One of the most important observations is that as the fiber and powder reinforcement increases the erosion wear rate decreases in composite material exposed to impingement of particles [20]. In this study the increase content of fiber and filler materials leads to improved erosion resistance because of the bonding between the base material and the reinforcing material which leads to improve mechanical properties, these results agree with [21]. Which may be related to its lower grain size with a good distribution and bonding and since RHA and CaCO 3 is harder, rise strength and stiffness than other filler.
The impingement angle is one of the generality significant parameters on the erosion behavior. Peak erosion takes place at (15° to 20° angle) for ductile materials, while peak erosion takes place at (90°angle) for brittle materials [22]. The erosion wear peak takes place at 30• and 90°, this behavior can be termed as (semi-ductile). The erosion wear rate high in the specimens reinforced with sawdust and K 2 CO 3 may be related to the poor linkage between matrix material and fillers with the matrix.

B. Coating:
The results of coating and erosion wear after coating for the pure epoxy and (natural, industrial) composites are illustrated in table 5. It is proposed to use the RHA with (particle experiment showed the best resistance to erosion among the industrial-based materials. The (pure epoxy) has been characterized by the following parameters; erosion time of (15 hours), a distance of (20 cm), (90°) of impingement angle, (850 μm) grain size, (30 Ċ) temperature, (200 gm) salt in (2 liters) of water. The weight of the investigated sample before coating is equal to (7.5743 gm), after coating the total weight amounted to (7.9042 gm) which corresponds to a coat thickness of (16 ± 1μm). After erosion wear test, sample weight has been found equal to (7.9030gm) with a loss of (0.0012 gm) from the coating layer only. The specimen (epoxy+6% glass fiber) has been characterized by the following parameters; erosion time of (15 hours), a distance of (20 cm), (60°) of impingement angle, (850 μm) grain size, (25 Ċ) temperature, (300 gm) salt in (2.5 liters) of water. The weight of the investigated sample before coating is equal to (8.3234gm), after coating the total weight amounted to (8.6623 gm). After erosion, the sample weight is found equal to (8.6614 gm) with a loss of (0.0009 gm) from the coating layer only. The specimen (epoxy+6% glass fiber +3%RHA) has been characterized by the following parameters; erosion time of (15 hours), a distance of (30 cm), (60°) of impingement angle, (850 μm) grain size, (25 Ċ) temperature, (200 gm) salt in (3 liters) of water. The weight of the investigated sample of experiment (17) before coating is equal to (8.4530 gm), after coating the total weight amounted to (8.7915 gm). After erosion, the sample weight is found equal to (8.7913 gm) with a loss of (0.0002 gm) from the coating layer only. The weight specimen (epoxy+6% glass fiber +6% RHA) before coating is equal to (8.7432 gm), after coating the total weight amounted to (9.0725 gm). After erosion, the sample weight is found equal to (9.0724 gm) with a loss of (0.0001 gm) from the coating layer only. The weight specimen (epoxy+6% glass fiber +3% carrot powder) before coating is equal to (8.7630 gm), after coating the total weight amounted to (9.1025 gm). After erosion, the sample weight is found equal to (9.1020 gm) with a loss of (0.0005 gm) from the coating layer only. The weight specimen (Epoxy+6%G.F+6% Carrot powder) before coating is equal to (9.0170 gm), after coating the total weight amounted to (9.3468 gm). After erosion, the sample weight is found equal to (9.3464 gm) with a loss of (0.0004 gm) from the coating layer only. The weight specimen (epoxy+6% glass fiber +3% sawdust) before
After erosion, the sample weight is found equal to (8.5581 gm) with a loss of (0.0008 gm) from the coating layer only. The weight specimen (epoxy+6% glass fiber +6% sawdust) before coating is equal to (8.5590 gm), after coating the total weight amounted to (8.8885 gm). After erosion, the sample weight is found equal to (8.8879 gm) with a loss of (0.0006 gm) from the coating layer only. The weight specimen (epoxy+6% glass fiber +3% Na2CO3) before coating is equal to (9.7650 gm), after coating the total weight amounted to (10.1031 gm). After erosion, the sample weight is found equal to (10.1026 gm) with a loss of (0.0005 gm) from the coating layer only. The weight specimen (epoxy+6% glass fiber +6% Na 2 CO 3 ) before coating has been equal to (10.2600 gm), after coating the total weight amounted to (10.5981 gm). After erosion, the sample weight is found equal to (10.5977 gm) with a loss of (0.0004 gm) from the coating layer only. The weight specimen (ep+6% g.f + 3% CaCO 3 ) before coating is equal to (7.6400 gm), after coating the total weight amounted to (7.9599 gm). After erosion, the sample weight is found equal to (7.9596 gm) with a loss of (0.0003 gm) from the coating layer only. The weight specimen (epoxy+6% glass fiber +6% CaCO 3 ) before coating is equal to (8.1760 gm), after coating the total weight amounted to (8.5139 gm). After erosion, the sample weight is found equal to (8.5137 gm) with a loss of (0.0002 gm) from the coating layer only. The weight specimen (epoxy+6% glass fiber +3% K 2 CO 3 ) before coating is equal to (8.1450 gm), after coating the total weight amounted to (8.4746 gm). After erosion, the sample weight is found equal to (8.4739 gm) with a loss of (0.0007 gm) from the coating layer only. The weight specimen (epoxy+6% glass fiber +6 %K 2 CO 3 ) before coating is equal to (8.4650 gm), after coating the total weight amounted to (8.8025 gm). After erosion, the sample weight is found equal to (8.8019gm) with a loss of (0.0006 gm) from the coating layer only.