Papers by Keyword: Scrap

Abstract: In this study, an attempt has been made to produce ductile iron or spheroidal graphite iron and to study its important properties with a view to reduce the import of machinery parts made of ductile iron. Locally available compressor scrap (i.e. the compressor cylinder) which is made from grey cast iron was used to produce ductile iron using a crucible furnace that is fired by oil. Also, recycling of the grey cast iron to ductile iron was investigated and its effect on the microstructure, chemical composition, mechanical properties and chip shape. The mechanical and structural characteristics of the ductile irons that alloyed by the supplement of Ni, Mo, Mg, and Cr were studied In this study, four kilograms of the scrap were charged into an oil-fired crucible furnace. The scrap was heated to 1400°C with using a temperature controller to monitor the temperature with an inserted thermocouple. For desulphurization, the mixture of 3 wt.% burnt lime with 1 wt.% fluorspar of scrap weight was added to the molten at 1400°C by direct tapping into the molten. Then, 2.75 wt.% nickel element, 0.75 wt.% ferromolybdenum and 0.5wt.% ferromanganese of the scrap weight were added. Also, 1.25 wt.% spheroidizing alloy (FeSiMg9) and 1wt.% inoculant alloy of scrap weight were used to treat the iron melt at 1450°C. The analysis of scrap sample and product sample was done to determine their chemical composition, tensile strength, impact strength, hardness, and microstructure. The scrap and the as-cast product analysis determine its chemical composition, tensile, impact, hardness and microstructure. The microstructures revealed that the scrap contains flake graphite and the as-cast product contains spheroid graphite. An increase of the ultimate tensile stress (537.17 MPa), elongation (10%), hardness value (480.4 HB) and impact value (11.21 J) was observed for the alloyed ductile iron as compared with the mechanical properties of grey cast iron scrap, including (247.75 MPa), (6%), (400.3 HB) and (5.66 J), respectively. One of the important conclusions is the plunge container manufactured, and that was used according to the plunging technique followed in this investigation proved successful

Abstract: The present scenario of energy conservation has witnessed many innovative and eco-friendly techniques and one such area where there is a necessity to conserve energy is foundries. Foundries also pollute the atmosphere with greenhouse gases contributing to 296143037.6 metric tons annually. The proposed technique in this paper aims at reducing the energy utilized in melting the scrap material at foundries by solar thermal energy. In the methodology proposed, solar energy is concentrated onto the scrap placed on a receiving platform using a parabolic trough and heats it up so that the heated scrap takes lesser energy to melt. The experiments resulted in preheating temperature of 100 °C when placed on a receiving platform and 110°C when copper shots are used to conduct heat from receiver to the scrap. This translates to energy conservation of 6%. This eco-friendly technique when adopted can result in substantial savings in consumption and environmental protection.

Abstract: Shaving is one of the precision shearing methods used to remove the rollover and fractured surface. The rollover and fractured surface formed in the punching stage are removed by shaving. It is expected that the rollover will be reduced when half punching with a negative clearance is carried out in the punching stage. In this study, the influence of the punch penetration depth in the punching stage on the cut edge after shaving was investigated. The results of this study clarified the followings: When the punch penetration depth in the punching stage with negative clearance is large, the sheared surface obtained by shaving after half punching with negative clearance is larger than that obtained by conventional punching. The sheared surface obtained by shaving after half punching with negative clearance increased with increasing the punch penetration depth in the punching stage with a negative clearance. The rollover produced by shaving after half punching with negative clearance is smaller than that produced by conventional shaving. In addition, the chip produced by shaving after half punching is connected to the sheet material under the punch. From the observed deformation of the chip produced in the shaving stage after half punching with negative clearance, the mechanism of shaving after half punching is considered to be cutting followed by shearing.

Abstract: Concept design of a scrap compactor is presented. Required data for the design of the scrap compactor, the hydraulic circuit, the compression ratio, force required for compression are collected from literature. The current practice of scarp removal and storage in a small scale industry is shown. The calculations for arriving at the force required for compaction is presented. The hydraulic circuit diagram and testing of the circuit in a pneumatic test bench are explained. Cost of the prototype and the break even period are discussed. Ergonomic principles and safety due to usage of scrap compactor are highlighted.

Abstract: In the last years and also due to today's economic situation and crises in the world, each organization is looking for a continuous improvement of processes and business performance. The major task of each production organization or services is the saving of money, which is lost because of scrap, long cycle times, wrong process maps and inventory differences. The goal of this article is to describe the implementation of Six Sigma in a production organization focusing on the production of interior parts for the automotive industry. During the summer time, there was delamination between thermoplastic foil and plastic substrate, which caused increasing of scrap, additional substandard works as well as the risk of quality complaints from customer. Six Sigma and DMAIC cycle were used to find root causes and to implement permanent corrective actions to remove this kind of problem from production.

Abstract: The present paper describes a method for predicting the imminence (hereafter referred as ‘quality’) of the chemical composition of a recycled alloy to that of a standard alloy of aluminum recycled alloy made from aluminum scrap (used automotive components). The present method allows the chemical composition of a recycled alloy to be predicted. The method has been validated experimentally, and the results obtained showed that the composition of the recycled alloy was close to that of the predicted one. These findings indicate that the present method can be successfully used for any other recycled alloys to predict the alloy composition based on the in-coming scrap alloys. In this work, the chemical composition of a synthesized recycled alloy was compared to an ASTM standard alloy with the nearest composition. It was found that the two compositions were very comparable. A deviation factor has been defined in order to understand the quality of the recycled alloy obtained with reference to the ASTM alloy.

Abstract: Cementing materials are one of the most indispensable materials for national economy and people's lives. In order to adapt new materials development demand and realize sustainable development, the present researches situation of new cementing materials have been summarized and analyzed from three aspects below: the usage of industrial wastes, organic materials, natural materials to develop new cementing material as well as developing other new cementing materials in the paper, and it also provided a reference for the new cementing material development.

Abstract: The surface cracking behaviors of Cu-bearing steels were studied under similar conditions of the direct hot charging processes. Several specimens with various Cu contents from 0.11 to 0.38% were prepared, the oxidation tests were performed at the temperature of 1100, 1150 and 1200°C, and the hot compression tests were conducted at 1050°C using the Gleeble 3500 in order to examine the Cu induced surface cracks. The surface cracks increased gradually as the Cu-rich phase above the critical level increased. The critical level of Cu-rich phase for the specimens of high Cu contents (0.38%) reaches with a thin scale layer. However, the specimens with lower Cu content (0.13%) the critical level of Cu-rich phase occurred with a thick scale layer. The oxidation potentials of steel were affected by temperature, time, atmosphere and other elements. The oxidation rates of Cu bearing steels decreased with increasing Cu contents. It is suggested that the oxidized scale thickness is the one of important factors inducing the surface cracks by Cu contained steels in direct hot charging process.

Abstract: Up to date, a reasonable and adequate process to treat magnesium scraps in die casting factory is not yet achieved, especially for middle or small scale die casters. Actually, many existing methods of handling magnesium scraps have met the level of technology for practical utilization requirement. Now, what we have to do is to propose a systematic handling process according to factory suitability and cost consideration. In this paper, the classification of magnesium scraps will be introduced first. Then the complementary storage methods and treatment methods for each type of scraps and recycle policy for die casters will be discussed. Finally, we propose a management model of magnesium scraps that is possibly suitable to some die casting factories.