DOCSLIB.ORG

Process Knowledge in Foundries by Dr.Hathibelagal Roshan Chief Metallurgist Maynard Steel Casting Company

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Process Knowledge in Foundries by Dr.Hathibelagal Roshan Chief Metallurgist Maynard Steel Casting Company Process knowledge in foundries By Dr.Hathibelagal Roshan Chief Metallurgist Maynard Steel Casting Company ABSTRACT: In order to be profitable, foundries need to have adequate process knowledge on the various processes used by them to manufacture the specific parts needed by their customers. In spite of a large number of publications on various aspects of metal casting processes, there appears to be a lack of gap in technology to specifically define process knowledge. Process knowledge is defined as the list of process variables, their collection system, visualization system and analysis to determine the ranges of relevant process variables that are related to the product characteristics for specific castings made in the foundries. It is not adequate to just focus on individual sub-processes in the foundry and try to control its process variables in a general way. It is essential to focus on the critical product characteristics that are related to the acceptance criteria and document the process knowledge relevant to the specific part. It is possible that the process knowledge relevant for one part need not be the same for another part in the same foundry. For example, in the melting of steel with Al content of 0.06 max may be satisfactory for one part and may not be adequate for another part that requires Al 0.03 max in order to meet the product characteristics requirement of the freedom from conchoidal fracture of the test specimens. INTRODUCTION: On average foundries lose a minimum of 5% of their revenue in internal and external failure costs. This indicates that foundries do not have the technology to produce castings without incurring these costs that could affect their profitability. We have a serious problem of Technology Gap in our foundry industry. The gap in technology lies in the lack of process knowledge in foundries and lack of adequate personnel trained in process control. PROCESS KNOWLEDGE: Process knowledge is defined as the list of process variables, their collection system, visualization system and analysis to determine the ranges of relevant process variables that are in deed related to the product characteristics for specific castings made in the foundries. BUSINESS PROCESS: Business process is a series of activities that are performed to produce a defined result. It has inputs which are transformed into outputs. The inputs can be data, material or state of things. Figure 1 shows the process hierarchy. Process in an organization can be divided into several levels such as Level 1 to Level 4 as indicated in figure 1. Level 1 contains highest level management process such as Casting Process. Level 1 process is decomposed into next lower level processes such as various sub-processes in Level 2. Figure 2 shows an example of process decomposition where Level 1 process is decomposed into level 2 processes. PROCESS CLASSIFICATION: In order to develop a computer based tool, there is a need for a hierarchal classification of the process and sub- process families. Figure 3 shows the taxonomy of the kingdom of PROCESS with part of shaping family expanded. The process kingdom has three families: shaping, joining and finishing. One of the families, namely shaping, is expanded to show classes namely: molding, deformation, casting etc. One these classes, namely casting is again expanded to show its members and sub-members. 1 METALCASTING PROCESS: Metal casting process is not a single process and has several Level 2 sub-processes. In order to define process knowledge, the various sub-processes can be identified as follows. The appropriate codes for each of the sub- processes are indicated in the parentheses against each of the sub-processes. Member Steel and sub-member Nobake are chosen for this classification. 1. Patternmaking/Methoding (GS-NB-1) 2. Molding (GS-NB-2) 3. Coremaking (GS-NB-3) 4. Melting (GS-NB-4) 5. Ladle/Pouring (GS-NB-5) 6. Shakeout (GS-NB-6) 7. Heat Treatment (GS-NB-7) 8. Welding (GS-NB-8) 9. Cleaning (GS-NB-9) PROCESS KNOWLEDGE: Process knowledge can be represented into the following components: 1. Factor Response Table (1) 2. Process Map – Box-Arrow Diagram (2) 3. Process Flow Chart (3) 4. Swimlane Process Map (4) 5. SIPOC diagram with FPRs (5) 6. Value Stream Map (6) 7. Cause and Effect Diagram (7) 8. Cause and Effect Matrix (8) 9. FMEA (9) 10. P-Matrix Case studies (10) 11. Published Literature (11) Examples of each of the above are given below 1. FACTOR RESPONSE TABLE: Responses are the outcome of processes that are relevant to either internal or external customers. For the purpose of defining process knowledge, the various responses are identified as follows: Major categories of responses are given below: Y1: Casting Dimensions Y2: Casting Defects Y3: DPMOs Y4: Quality Costs 2 Each of the above major response categories are again expanded to sub-categories of responses as indicated below. Code Name Y1-1 Casting Dimensions Y2-1 Runout Y2-2 Inclusions Y2-3 Shrinkage Y2-4 Misrun Y2-5 Erosion Y2-6 Penetration Y2-7 Hot Tear Y2-8 Type II Sulfides Y2-9 Incorrect impacts Y2-10 Incorrect mechanicals Y2-11 Blowholes- Pinholes Y2-12 Cracks Y2-13 Broken Molds Y2-14 Flash Y3-1 DPMO-Redlights Y3-2 DPMO-Missed Deliveries Y3-3 DPMO-Quality issues Y3-4 DPMO-Retests Y3-5 DPMO-ReHeatTreats Y4-1 Quality Cost-Internal Failure Y4-2 Quality Cost-External Failure It is necessary to determine which responses are relevant to the various sub-processes in the foundry. Also, it is necessary to identify the various factors and the corresponding responses in the various sub-processes in the foundry. Examples of process knowledge in the form of Factor-Response tables relating to the various sub- processes are shown in tables 1 to 9 below. 3 Table 1: PATTERNMAKING/METHODING (GS-NB-1-1) Response Remarks on significance of factor in r of (Y) relation to the response od Sub- (X) nos/ Meth Meas Discr Prt Spc Conti Facto uremt Casting Units Pattern Flatness Calibrated Inches Continu Casting Generally ribs are placed under the pattern board (X1-1) Straight Edge ous Dimension Y1-1 to support the weight of the pattern and the weight of sand during moldmaking. The pattern board shall not sag enough to distort the parting line Patter Shrink Calibrated Correct/ Discrete Critical Casting Choosing the appropriate shrink rule is essential Rule, Straight Edge Incorrect Dimensions for correct casting dimensions. Verify whehter % (X1-2) Y1-2..N the pattern and core boxes are made to correct shrink rule Casting to Flask Tape Inches Continu Casting Defect Correct selection of flask size and its relationship Relationship Measurement ous (RunOut) Y2-1 to the gating as well as casting to the flask wall (X1-3) are important to minimize metal penetrating to the flask during mold filling. If the metal is too close to the wall, the potential for the metal penetrating the wall will be high. Core print areas also need to be considered Gating Ratio Tape Yes/No Discrete Casting Defect Gating ratio is defined as the SprueBase Area: (X1-4) Measurement (Inclusions) Total Runner Area: Total Ingate Area. In a and Y2-2 pressurized gating system, choke exists at the calculation ingate and controls the flow rate. In a non- pressurized gating system, choke does not exist at the ingate and will be upstream, either in the runner or at the sprue base. For gray irons and ductile irons, a pressurized gating system is generally used. For Aluminum alloys and steels, a non-pressurized system is used. Location of Visual Yes/No Discrete Casting Defect In a pressurized gating system, runner should ingates and observation (Inclusions) be in cope and the ingates also in the cope at runner relative Y2-2 the parting surface. In the Non-Pressurized to the parting gating system, runner should be in the drag surface and the ingates in the cope at the parting (X1-5) surface. 1. Patternmaking / Methoding Type of Gating: Visual Yes/No Discrete Casting Defect Bottom gating is preferred for steel castings. Bottom/Parting observation (Inclusions) Line/Fountain/T Y2-2 angential (X1-6) Compatible Visual Yes/No Discrete Casting Defect nozzle diameter observation (Inclusions) to Sprue Y2-2 Diameter in bottom pour ladles (X1-7) Modulus Ratio Tape Yes/No Discrete Casting Defect Modulus ratio is defined as the ratio of (X1-8) Measurement (Shrinkage) Y2-3 casting modulus: Riser neck Modulus: Riser and Modulus.In general the ratio should be 1: 1.1: calculation 1.2 for steel castings. Verify whether you have a satisfactory modulus ratio Total Weight of Weight Yes/No Discrete Casting Defect Available feed metal from a cylindrical sand the risers in Measurement (Shrinkage) Y2-3 riser is 10-12% available feed metal from a relation to the and conical sand riser is 15-20% available feed casting weight calculation metal from a insulating sleeve riser is 20% plus gating available feed metal from an exothermic system (X1-9) sleeve riser is 30%. Based on the type of riser, verify whether your riser weight is adequate or not 4 Table 1: PATTERNMAKING/METHODING (GS-NB-1-1)(Contd.) e g Response Remarks on significance of factor in s/ of mt (X) Sub- C/D Ran (Y) relation to the response Prt Spc Process Casting Method Units Contino Factor Discrete Discrete Measure Blind Riser Visual Yes/No Discrete Casting Defect Care should be taken while designing the blind Design with observation (Shrinkage) Y2-3 risers. They will be effective only when the Williams Core atmospheric pressure acts on the liquid metal (X1-10) inside the riser. Williams cores or V-notches need to be provided on the blind risers to permit the atmospheric pressure act on the blind risers.
Load more

Recommended publications
  • Compression Behavior of Entrapped Gas in High Pressure Diecasting
    Materials Transactions, Vol. 53, No. 3 (2012) pp. 483 to 488 ©2012 Japan Foundry Engineering Society Compression Behavior of Entrapped Gas in High Pressure Diecasting Yasushi Iwata, Shuxin Dong, Yoshio Sugiyama and Hiroaki Iwahori Toyota Central R&D Labs., Inc., Nagakute 480-1192, Japan Die castings generally contain a large quantity of porosities due to the entrapment of air or gas in molten metal during mold filling. Although the entrapped air or gas is compressed by high casting pressure during pressurization, it will eventually remain in the castings as defects after solidification. Therefore, it is important to clarify the relation between the volume of gas defects and the pressure applied to the molten metal so as to optimize the casting design. In this study, we investigated the compression behavior of entrapped gas during casting. We determined the volume of gas defects and gas content in die castings by density measurement and vacuum fusion extraction method respectively. Then we calculated the gas pressure in the defects from the above volume of defects and gas content, and compared with the die casting pressure. The calculated gas pressure in the defects was found to be not equal to the die casting pressure, but equal to the pressure of the molten metal just before it dropped abruptly due to the complete blocking of the liquid metal channel by solidification. From the experimental results, the behavior of the entrapped gas can be inferred as follows. Immediately after the mold was filled with molten metal, the entrapped gas was instantly compressed. After that, the pressure of molten metal decreased gradually with the progress of solidification of the molten metal channel, and the volume of entrapped gas increased correspondingly until the pressure of the molten metal dropped abruptly.
    [Show full text]
  • Defect Analysis for Sand Casting Process (Case Study in Foundry of Kombolcha Textile Share Company)
    International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 07 Issue: 01 | Jan 2020 www.irjet.net p-ISSN: 2395-0072 Defect Analysis for Sand Casting process (Case Study in foundry of Kombolcha Textile Share Company) Wossenu Ali Wollo University, Kombolcha Institute of Technology, Mechanical Engineering Department, Kombolcha, Ethiopia ---------------------------------------------------------------------***---------------------------------------------------------------------- Abstract - This research aimed to identify the cause of casting product. Deviation of any process parameter casting defect and to suggest possible remedies in order will cause one or more casting defects on the product. to produce conforming casting product in the foundry of Kombolcha textile share company, Ethiopia. During A few manufacturing industries are found in Ethiopia casting defect analysis, the common casting defects in which casting process is the one that uses to produce blowholes, pinholes and shrinkage were identified. The metallic parts. These parts use for internal customers major and minor process variables which were who wants to substitute their broken spare parts. Since responsible for each casting defects were indicated using the process is supported by shop-floor trial and there is fishbone diagram. For analysis of possible causes, shortage of skilled workers, the casting products Experiments were conducted for moulding sand to produced are not quality product to satisfy customers determine clay content and grain fineness number need. Solving this problem in these foundries is (GFN). For defective part, composition analysis using important to satisfy customers need. spectrometer was also done. Analysis showed that high Casting process in foundry of Kombolcha textile clay content (52.7%) of moulding sand, wrong gating Share Company produces parts such as Armature disk, system design, incorrect pattern design and unknown front flange, real flange, and pulley of different size, pouring temperature were responsible for the defects.
    [Show full text]
  • Minimization of Casting Defects in Aluminum Alloy Wheels of Grade A356.2 K.Pundari Kaksha #1 P.Satish Reddy #2 N.Guru Murthy #3 S.Siva Kumar #4 PG Scholar, Assoc
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by International Journal of Science Engineering and Advance Technology (IJSEAT) ISSN 2321-6905 February- 2018 International Journal of Science Engineering and Advance Technology, IJSEAT, Vol. 6, Issue 2 Minimization of Casting Defects In Aluminum Alloy Wheels of Grade A356.2 K.Pundari Kaksha #1 P.Satish Reddy #2 N.Guru Murthy #3 S.Siva Kumar #4 PG Scholar, Assoc. Professor, Asst Professor, Asst Professor Dept of Mechanical Engineering, Prasiddha College of Engg & Tech, Anathavaram [email protected],[email protected],[email protected], [email protected] So, precautions should be taken while casting the wheel. Throughout the production of aluminum ABSTRACT: alloy wheels the typically used raw material is Al- The primary motive of this project is Si casting alloys. As of their good casting identification of the casting defects in Aluminium properties and due to these alloys will provide good alloy wheels, to reduce the losses due to scrap and corrosion resistance and strength so that vehicle rework and also applications of techniques to can acclimatize to road and weather condition. reduce the defects to a minimum level. To identify 1.1 A356.2-COMPOSITION: the defects in the product, the process adopted in casting, inspection and testing procedures are Al - 92.4% studied. Reasons for defects in hub, spoke and rim Si - 6.5%-7.5% are identified. Number of defects occurred in hub, spoke and rim are collected and techniques to Mg - 0.25-0.45% minimize these are suggested.
    [Show full text]
  • A Work Study on Minimize the Defect in Aluminium Casting
    International Journal of Emerging Technologies in Engineering Research (IJETER) Volume 3, Issue 1, October (2015) www.ijeter.everscience.org A Work Study on Minimize the Defect in Aluminium Casting Er. Satish Kumar Assistant Professor, M.E Department, Dungarpur College of Engineering and Technology, Dungarpur (Raj), India. Er. Amit Tiwari Research Scholar, (Production Engineering), Pacific University, Udaipur, Rajasthan, India. Abstract – In the present world with the increasing use of pressure of dry air (0.5 ~ 1.0 kg/mm2) on the surface of molten Aluminium alloy wheels in automotive industry the Aluminium metal in the bath. The pressure causes the metal to rise through foundry industry had to focus on the quality of the products. The a central Ceramic riser tube into the die cavity. The dies are quality of a foundry industry can be increased by minimizing the provided ample venting to allow escape of air, the pressure is casting defects during production. Aim of the current study is to maintained till the metal is solidified ; then it is released study the production line of an aluminium alloy wheel manufacturing industry and to improve the quality of production enabling the excess liquid metal to drain down the connecting using quality control tools. This study shows the systematic tube back in to the bath. Since this system of upward filling approach to find the root cause of major defects in aluminium requires no runners and risers, there is rarely any wastage of castings using defect diagnostic approach as well as cause and metal. As positive pressure maintained to force the metal to fill effect diagram.
    [Show full text]
  • The PEWTER COLLECTORS' CLUB of AMERICA INC
    The PEWTER COLLECTORS' CLUB ofAMERICA INC. THE BUllETIN Summer 2004 Volume 13 Number 1 PCCA Officers President ................................................ Richard C. Graver First Vice President ................................... David M. Kilroy Second Vice President ................... Robert G. Eisenbraun Treasurer ....................................................... Terry 1. Ashley Secretary ........................................................ Robert Horan Bulletin Editor Garland Pass 71 Hurdle Fence Drive Avon, CT 06001-4103 Email: [email protected] Editorial Board Garland Pass, Chair William R. Snow Richard Bowen Charles V. Swain Wayne A. Hilt Melvyn D. Wolf For the names and addresses of all club officers and committee heads, please refer to the latest issue of the PCCA Membership Directory TABLE OF CONTENTS Page 2 .......................................... President's Letter, Richard C Graver Page 3 .......................................... Folk Art Engraving on Pewter, Garland Pass Page 34 ......................................... Pewter Imports 1750, Charles V. Swain Page 35 .......................................... Boardman Measure of 1818, Andrew F Turano Page 36 ......................................... A New Gleason Candlestick, Melvyn D. Wolf, M.D. Page 37 .......................................... Copper Bottom Teapots, Melvyn D. Wolf, M.D. Page 38 .......................................... New York Handle Porringers Addendum, Melvyn D. Wolf, M.D. Page 39 .......................................... The Other Relief
    [Show full text]
  • Computers in Foundries
    Computers in Foundries Dr Thoguluva Raghavan Vijayaram* and Dr Paolo Piccardo** * Principal Lecturer, Faculty of Engineering and Technology, FET MMU, Multimedia University, Melaka Campus Melaka, Malaysia ** Professor, Dipartimento di Chimicae Chimica Industriale, DCCI, Sezione di Chimica Inorganicae Metallurgia, Genoa University, Genoa, Italy ABSTRACT RIASSUNTO Computers have now entered into the foundry I computer sono entrati prepotentemente nella fonderia, engineering. Foundry mechanization and modernization un’arte antica che si è evoluta in una scienza moderna. La are of considerable importance today when the foundry fonderia è oggi completamente monitorata e controllata has evolved from an ancient art into a modern science dal computer, che assume un’importanza primaria per and it is fully controlled and monitored by computers. migliorare la qualità dei getti e la produttività. Dal punto Modernization is the only key to improve casting quality di vista industriale, i PC sono da tempo utilizzati nelle and productivity. From industrial point of view, they aree amministrative della finanza, contabilità, gestione have been in use in the administrative areas of finance, del personale, salari, stipendi, gestione del magazzino. accounting, personnel records, wage, salaries, and Attualmente molti sistemi di macchine per fonderia sono inventory control for a long period. Many foundry machine computerizzati. Grazie al computer la fatica e lo stress systems are computerized. Due to the entry of computers per i lavoratori e lo staff si sono ridotti notevolmente. La in foundries, fatigue and strain on the workers and staffs cultura del lavoro è notevolmente migliorata, e con essa si have been considerably reduced during working and sono sviluppati il coinvolgimento, la creatività e il senso di work culture has improved tremendously.
    [Show full text]
  • Introduction to Casting for 3D Printed Jewelry Patterns the Way Jewelers Work Is Changing, and Castable Photopolymer Resins Are Leading the Way
    Introduction to Casting for 3D Printed Jewelry Patterns The way jewelers work is changing, and castable photopolymer resins are leading the way. From independent designers concepting and prototyping in their studios, to casting houses increasing capacity and diversifying their offerings, digital fabrication techniques are increasingly key to growing a successful jewelry business. In this guide, learn how to cast fine jewelry pieces from patterns 3D printed on the Form 2. Request a Sample Part 3D Printed in Castable Wax Resin › Learn About Casting and Jewelry Production from Formlabs › July 2019 | formlabs.com What Is Direct Investment Casting? Direct investment casting, or lost wax casting, is a popular moldmaking technique that can be used to fabricate small and large parts in a wide variety of metals. Originating over 5,000 years ago, casting enables creators to work with a wide variety of materials and is one of the easiest ways to make metal parts. In investment casting, a hollow mold is created from a hand-sculpted or 3D printed master pattern. The master is immersed in a refractory casting material (or “investment”), which dries and hardens. The wax or 3D printed pattern is burned out, leaving a negative mold of the design. Metal is poured into this hollow cavity to create the final part. Wax patterns for intricate jewelry are complicated to produce by hand, and in a world driven by high demand and fast fashion, it can be difficult for hand-crafted pieces to keep pace. Advanced materials and affordable in-house 3D printers like the Form 2 are changing the way jewelry manufacturers and designers work, bringing industrial quality to the desktop and making it easier to produce and fit complicated geometries that once required hours of meticulous labor.
    [Show full text]
  • SIMPLE SOLUTIONS THAT WORK! Committed to Sharing Best Practices for the Metalcasting and Die Casting Industry
    ENGLISH / ESPAÑOL ISSUE 13 • FALL 2020 SIMPLE SOLUTIONS THAT WORK! Committed to sharing best practices for the metalcasting and die casting industry THE FOCUS OF THIS ISSUE: Defect Prevention WELCOME TO OUR “DEFECT PREVENTION” ISSUE With so many ways to make a bad casting, it’s no wonder that metal casters have taken a leadership position in the manufacturing world by building quality—in from the start. Unlike other manufacturing processes that rely heavily on final inspection as a primary means of ensuring quality, foundries understand better than others that you can’t wait until the casting is machined to test it. Over the past ten years, the foundry production floor has literally been upended with important changes, all designed to produce higher quality parts, at less cost—with reduced scrap. Six Sigma principles, robotic workcells, Additive Manufacturing, and Smart Technologies are all being deployed to deliver higher quality castings with repeatable processes. Today, everyone on the foundry floor is involved in the prevention of defects and this work is never, ever done. This issue is devoted to this subject because it’s something that you can’t talk about enough. We hope you find the defect prevention ideas in this issue (that range from binders and the mixing process, melting, analysis, materials, and molding) techniques you can use today. I would like to thank all of our contributors in this issue for their insightful articles. Special thanks to Innovative Casting Technologies, Dualtech Foundry’s Laboratory Manager Scott Gill for appearing on the cover of this issue. As always, thank you for reading our 13th issue of Simple Solutions That Work! GET THE FREE APP! Jack Palmer President, Palmer Manufacturing & Supply, Inc.
    [Show full text]
  • Opinnäytetyön Asettelumalli
    Kristian Anttila SIX SIGMA TO IMPROVE QUALITY – COMPONENTA CASE International Business Degree Programme in SAMK 2019 SIX SIGMA LAADUN PARANTAMISEKSI – COMPONENTA CASE Anttila Kristian Satakunnan Ammattikorkeakoulu kansainvälisen kaupan koulutusohjelma Joulukuu 2019 Sivumäärä: 49 Liitteitä: 1 Asiasanat: Laadun valvonta, Six Sigma, DMAIC, Prosessi, Valimo ____________________________________________________________________ Tämä opinnäytetyö käsittelee laadun valvontaa. Työ on tehty yhteistyössä Componenta Pori:n kanssa, valimo joka sijaitsee Suomessa. Työ on prosessin hallinnasta ja kuinka parantaa yleisesti laatua muutamasta valitusta prosessita tuotantolinjassa. 3 Prosessia tuotantolinjasta ollaan huomattu tekevän huonoja tuotteita joka ylittää yhtiön keskimäärän eli 8% valmistuneista tuotteista. Kyseiset prosessit ovat muotin valmistus, ytimien sijoittaminen muottiin sekä molempien muottien puoliskoiden yhdistäminen, työ avaa näitä prosesseja analyyttisesti hypoteesein sekä parannus ehdotuksin. Teoria, jota työssä käytetään, on Six Sigma, tarkemmin DMAIC prosessi työkalu joka tukee työtä antamalla työkalut prosessin parannukseen sekä laadun hallintaan. Toiminta-analyyttinen toimintaotetta käytetään työssä jota tukee havainnointi, haastattelu sekä työntekijöiden kommentit. Käytännön testit hypoteeseille eivät ollut mahdolisia joten oikeita tuloksia kyseisistä hy poteeseista ei saatu. Lopullinen työ voi parantaa yhtiön työympäristöä prosessien sekä työntekijöiden kannalta, jos kyseiset ehdotukset otettaisiin huomioon. Parannusehdotukset
    [Show full text]
  • Casting Defects Analysis in Foundry and Their Remedial Measures with Industrial Case Studies
    IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 12, Issue 6 Ver. I (Nov. - Dec. 2015), PP 43-54 www.iosrjournals.org Casting Defects Analysis in Foundry and Their Remedial Measures with Industrial Case Studies Avinash Juriani1 1(M.tech Scholar, Department of Mechanical Engineering, Indian School of Mines, Dhanbad, Jharkhand, India) Abstract: In this current scenario of globalization, foundries play a key role for manufacturing industries as they are the major source of castings. As a key industry a foundry’s performance should be effectively high in terms of production with minimum number of rejections. Castings are the major inputs for most industrial products hence foundry industry is most indispensable. Casting is an integrated process considered as an artwork with experienced professionals for high quality yield, even then in highly controlled environment defects are dominant to take place leading to rejections, contrary to rejections a foundry’s key attempt is to satisfy the demands neglecting quality levels. The challenges of casting defects are to be identified and minimized for effective castings. This study provides an intense knowledge of critical casting defects and their root cause analysis. In this paper efforts are made to achieve technically feasible remedies for minimizing several casting defects and improving the quality of castings which will serve as control measures for quality control professionals with zero defect concepts. Keywords: Casting Defects, Cause and Effect Diagram, Centrifugal Casting, Defects Analysis. I. Introduction Defects formation in castings is one of the most vexed topics of foundry industries.
    [Show full text]
  • Defect Minimization in Casting Through Process Improvement-A Literature Review
    IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 14, Issue 2 Ver. I (Mar. - Apr. 2017), PP 09-13 www.iosrjournals.org Defect Minimization in Casting through Process Improvement-A Literature Review Mr. Patil Sachin S.1, Prof. Naik Girish R.2 P.G. Student, Department of Production Engineering, KIT’s College of Engg, Kolhapur, India1 Associate Professor, Dept. of Production Engineering, KIT’s College of Engg, Kolhapur, India2 Abstract: In India many foundries have followed conventional and manual operations. Foundry industries suffer from poor quality and productivity due to large number of process parameters combined with lower penetration of automation and shortage of skilled worker. Mould shifting, sand inclusions, poor surface finish, shrinkage, porosity, cold shut and flash are common casting defects in casting. Since casting process involves complex interaction among various parameters and operations related to metal composition, method designs, melting, pouring, shake-out, fettling and machining and hence need to improve. This Paper prescribes comprehensive review of work pertaining to process improvement techniques used for defect minimisation in casting. Keywords: Casting design, Casting defect, Cause of defects, Yield improvement, Process improvement. I. Introduction Green sand casting process is a versatile process because it can be used for casting of most metals with high melting point temperatures like copper, cast iron. Several types of defects may occur during casting, considerably reducing the total output of castings. Defects may be defined as those characteristics that create a deficiency or imperfection differing to the quality specifications imposed by the design and the service requirements.
    [Show full text]
  • Shell Mold Casting
    Shell Mold Casting Shell mold casting or shell molding is a metal casting process in manufacturing industry in which the mold is a thin hardened shell of sand and thermosetting resin binder backed up by some other material. Shell mold casting is particularly suitable for steel castings under 10 kg; however almost any metal that can be cast in sand can be cast with shell molding process. Also much larger parts have been manufactured with shell molding. Typical parts manufactured in industry using the shell mold casting process include cylinder heads, gears, bushings, connecting rods, camshafts and valve bodies. The Process The first step in the shell mold casting process is to manufacture the shell mold. The sand we use for the shell molding process is of a much smaller grain size than the typical greensand mold. This fine grained sand is mixed with a thermosetting resin binder. A special metal pattern is coated with a parting agent; (typically silicone), which will latter facilitate in the removal of the shell. The metal pattern is then heated to a temperature of (175 °C-370 °C) . The sand mixture is then poured or blown over the hot casting pattern. Due to the reaction of the thermosetting resin with the hot metal pattern a thin shell forms on the surface of the pattern. The desired thickness of the shell is dependent upon the strength requirements of the mold for the particular metal casting application. A typical industrial manufacturing mold for a shell molding casting process could be 7.5mm thick. The thickness of the mold can be controlled by the length of time the sand mixture is in contact with the metal casting pattern.
    [Show full text]