scholarly journals The Sources of Surface Defects in Castings Produced in Automated Process Lines

2015 ◽  
Vol 15 (4) ◽  
pp. 91-94 ◽  
Author(s):  
R. Wron ◽  
M. Brzeziński ◽  
E. Ziółkowski
Keyword(s):  
Surface Defects ◽  
Casting Process ◽  
Quality Parameters ◽  
Molten Metals ◽  
Moisture Contents ◽  
Slag Inclusions ◽  
Iron Foundry ◽  
Metallic Compounds ◽  
Process Line ◽  
Automated Process

Abstract This study summarises the research efforts undertaken in iron foundry plants in which the process are mostly automated and mechanised. The research program was limited in scope, focusing on causes of surface defects in castings products that are attributable to the bentonite-containing sand and the mould system. One of the potential roots of surface defects is heterogeneity of sand grains, containing lumped ball-shaped grains and irregular pellets with a layered-structure. The moisture contents of those lumped grains is different than the moisture level required in the process, besides these grains may contain various elements and metallic compounds which, when cast into moulds, may react with molten metals in an uncontrolled manner. As a result, surface defects are produced, such as surface blowholes, burst penetration, sand holes, slag inclusions, pinhole porosity. This study investigated the efficiency of key sand preparation and moulding machines and installations integrated into the casting process line. The efficiency of machines and installations is defined in terms of quality parameters of sand mix and moulds, which are associated with the emergence of surface defects on castings.

scholarly journals Development of Data-Driven Machine Learning Models for the Prediction of Casting Surface Defects

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Shikun Chen ◽  
Tim Kaufmann
Keyword(s):  
Machine Learning ◽  
Cast Iron ◽  
Surface Defects ◽  
Casting Process ◽  
Machine Learning Algorithms ◽  
Casting Surface ◽  
Iron And Steel ◽  
Related Data ◽  
Iron Foundry ◽  
Related Defect

This paper presents an approach for the application of machine learning in the prediction and understanding of casting surface related defects. The manner by which production data from a steel and cast iron foundry can be used to create models for predicting casting surface related defect is demonstrated. The data used for the model creation were collected from a medium-sized steel and cast iron foundry in which components ranging from 1 to 100 kg in weight are produced from wear and heat resistant cast iron and steel materials. This includes all production-relevant data from the melting and casting process, as well as from the mold production, the sand preparation and component quality related data from the quality management department. The data are tethered together with each other, the information regarding the identity and number of components that resulted in scrap due to the casting surface defect metal penetrations was added to the dataset. Six different machine learning algorithms were trained and an interpretation of the models outputs was accomplished with the application of the SHAP framework.

OPTIMISATION OF SAND CASTING PROCESS FOR IMPELLER USING TAGUCHI METHODOLOGY

2020 ◽  
Vol XVII (2) ◽  
pp. 23-33
Author(s):  
Faisal Hafeez ◽  
Salman Hussain ◽  
Wasim Ahmad ◽  
Mirza Jahanzaib
Keyword(s):  
Surface Roughness ◽  
Surface Defects ◽  
A356 Alloy ◽  
Casting Process ◽  
Sand Casting ◽  
Gate Length ◽  
Taguchi Methodology ◽  
Confirmatory Tests ◽  
Binder Ratio ◽  
Response Measures

This paper presents the study to investigate the effects of binder ratio, in-gate length and pouring height on hardness, surface roughness and casting defects of sand casting process. Taguchi methodology with L9 orthogonal array was employed to design the experimentation. Sand casting of six blade impeller using A356 alloy was performed and empirical models for all the above response measures were formulated. Confirmatory tests and analysis of variance results confirmed the accuracy of the model. Binder ratio was found to be the most significant parameter affecting casting surface defects and surface roughness. This was followed by pouring height and in-gate length.

The Effect of Temperature Fluctuation on the Formation of Billet Surface Defect in the Initial Solidification Area

2010 ◽  
Vol 148-149 ◽  
pp. 163-167
Author(s):  
Xiao Li Jin ◽  
Zuo Sheng Lei ◽  
Kang Deng ◽  
Zhong Ming Ren
Keyword(s):  
Continuous Casting ◽  
Temperature Fluctuation ◽  
Surface Defects ◽  
Casting Process ◽  
Effect Of Temperature ◽  
Billet Surface ◽  
Maximum Value ◽  
Key Factor ◽  
Oscillation Marks ◽  
Initial Solidification

The heat transfer in steel continuous casting process under mold oscillation was calculated, and temperature fluctuation phenomena was found in the initial solidification area, the maximum value was approximate 16 °C. The effect of different continuous casting parameters on temperature fluctuation were analyzed, and the temperature fluctuation was considered to be a key factor to the formation of oscillation marks. The Index of Temperature Fluctuation(ITF) was proposed to predict the effect of temperature fluctuation on the formation of billet surface defects.

scholarly journals Microstructure Examinations in Corners of the Low-Carbon Steel Slabs from Continuos Caster Machine

2016 ◽  
Vol 61 (4) ◽  
pp. 2051-2056 ◽  
Author(s):  
G. Kwinta ◽  
S. Kara ◽  
B. Kalandyk ◽  
R. Zapała ◽  
P. Pałka
Keyword(s):  
Surface Defects ◽  
Cast Steel ◽  
Continuous Process ◽  
Low Carbon Steel ◽  
Casting Process ◽  
American Petroleum Institute ◽  
Test Material ◽  
Low Carbon ◽  
Destructive Testing ◽  
Gaseous Fuels

Abstract The exposed selvedge layers in slabs cast by the continuous process should be free from surface defects, which in most cases appear in the form of cracks on the casting surface and run to its interior. In addition to the parameters of the casting process, the occurrence of such defects depends on the chemical composition of cast steel, on the segregation of surface active elements and formation of the precipitates of carbides, nitrides and other phases. Due to the frequent occurrence of defects in corners of the slabs, non-destructive testing was performed on the mechanically cleaned surfaces of slabs. The test material was low-carbon API(American Petroleum Institute API 5L standard) steel micro alloyed with Nb and Ti designed for the production of pipes to handle gas, oil and other liquid and gaseous fuels. Despite the use of different methods of inspection, i.e. ultrasonic, magnetic particle and penetrant, cracks were not traced in the examined material. Then, from the corners of the examined slabs, specimens were cut out for metallographic examinations. The main purpose of these examinations was to disclose the presence of possible cracks and micro cracks on the surfaces transversal and longitudinal to the direction of casting. At the same time, studies were conducted to establish the number and morphology of non-metallic inclusions in selvedge layers of the slab corners and axis. Additionally, hardness of the slabs was measured. The conducted studies revealed only some minor differences in the slab hardness along its axis (130 ÷ 135 HB) and in selvedge layers (120 ÷ 123 HB).

scholarly journals Minimising Defect Formation in Sand Casting of Sheet Lead: A DoE Approach

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 252
Author(s):  
Arun Prabhakar ◽  
Michail Papanikolaou ◽  
Konstantinos Salonitis ◽  
Mark Jolly
Keyword(s):  
Process Parameters ◽  
Surface Defects ◽  
Defect Formation ◽  
Casting Process ◽  
Sand Casting ◽  
Sand Cast ◽  
Factors Affecting ◽  
Screening Experiments ◽  
Traditional Manufacturing ◽  
Lead Sheet

Sand casting of lead sheet is a traditional manufacturing process used up to the present due to the special features of sand cast sheet such as their attractive sheen. Similarly to any casting process, sand casting of lead sheet suffers from the presence of surface defects. In this study, a surface defect type, hereby referred to as ‘grooves’, has been investigated. The focus has been laid on the identification of the main factors affecting defect formation in this process. Based on a set of screening experiments performed using Scanning Electron Microscopy (SEM) as well as the existing literature, a number of factors affecting the formation of such defects was identified and their corresponding significance was estimated using the Analysis of Variance (ANOVA) technique. The obtained results suggest that the most significant factor affecting defect formation in sand casting of lead sheet is the composition of the moulding mixture. Defect formation was also proven to be dependent on the sand grain fineness, the quality of the melt and some of the interactions between the aforementioned process parameters. Finally, an optimal set of process parameters leading to the minimisation of surface defects was identified.

Using Simulation to Improve the Quality of the Metallic Industrial Components Made by Rapid Casting

2015 ◽  
Vol 808 ◽  
pp. 187-192
Author(s):  
Alina Popan ◽  
Nicolae Bâlc ◽  
Alexandru Popan ◽  
Nicolae Panc ◽  
Cristina Stefana Borzan
Keyword(s):  
Surface Defects ◽  
Casting Process ◽  
Complex Geometries ◽  
Thin Sections ◽  
Vacuum Casting ◽  
Rapid Casting ◽  
Casting Technology ◽  
Small Series ◽  
Complex Shapes

Industrial parts with complex shapes are characterized by thin sections and complex geometries. Rapid vacuum casting is an ideal technology to manufacture complicated parts in small series production or prototypes. Contributions regarding simulation and analyzing of the parts made by rapid vacuum casting technology are presented in this study. Using dedicated software for simulating the casting process was analyzed and optimized the time of casting, the complete filling with material and also reducing the surface defects.

Analysis of the defects occurrence on the functional surfaces of individual mould segments for the tyre production from AlSi7Mg0.3Sr

2020 ◽  
Vol 234 (17) ◽  
pp. 3474-3483 ◽  
Author(s):  
I Hren ◽  
S Michna ◽  
J Svobodova ◽  
L Michnova ◽  
L Benes
Keyword(s):  
Electron Microscopy ◽  
Cross Sections ◽  
Surface Defects ◽  
Subsurface Layer ◽  
Light And Electron Microscopy ◽  
Microstructural Characterization ◽  
Casting Process ◽  
Functional Surface ◽  
X Ray ◽  
Functional Surfaces

The basic prerequisite for obtaining a quality casting according to the requirements and specifics of the customer is the production of the mould (in our case using low-pressure die-casting) without the occurrence of surface defects in the form of cracks, scabs, microshrinkages and local depressions. In this case, the mould segments for the tyre production are those which show tiny cracks or scabs on the functional surface of the castings that define the surface quality of the resulting product. It is necessary to analyse these defects in order to eliminate the causes of their formation in the casting process. For this reason, a new alloy of eutectic silumin AlSi9 alloyed with Mg, Mn and modified Sr was prepared in order to improve the fluidity and maintain the mechanical properties of the material up to 250 ℃ The subject of the study was the analysis of the surface defects of the mould, including the analysis of the chemical composition (energy-dispersive X-ray) and microstructure in the defect area. In order to investigate the subsurface layer of defects, metallographic specimens of cross-sections were prepared by means of mould, which were examined by light and electron microscopy. The detailed microstructural characterization of individual elements was performed on lamellas of the mould studied using transmission electron microscopy. An X-ray diffraction analysis was performed to investigate the residual stress at the defects area very closely. It has been found that a smaller number of defects on the functional surfaces can be obtained by changing the mould position during casting.

Numerical Modeling of Planar Flow Casting Process

2006 ◽  
Vol 116-117 ◽  
pp. 106-109 ◽  
Author(s):  
Kee Hyeon Cho ◽  
Kee Ahn Lee ◽  
Moon Chul Kim ◽  
Joong Mook Yoon
Keyword(s):  
Heat Transfer ◽  
Process Parameters ◽  
Casting Process ◽  
Computational Domain ◽  
Molten Metals ◽  
Planar Flow ◽  
Planar Flow Casting ◽  
Flow Heat ◽  
Fully Coupled ◽  
Heat Transfer And Solidification

This study sought to examine the effect of various process parameters on the thickness of the amorphous strip produced by Planar Flow Casting (PFC), which is used to solidify molten metals rapidly. The processes were simulated via fully coupled fluid flow, heat transfer, and solidification models. The temperature distribution and velocity profile of melt in the computational domain with given process parameters were investigated according to various melt inlet temperatures, size of gap between nozzle slots, rotating wheel, and ejection pressure. In general, stable shaping of ribbons was obtained given a heat transfer coefficient of 100 cal/cm2/sec/°C. Strip thickness was found to decrease with the pouring temperature of melt. The results evaluated based on the numerical model were verified based on experimentally measured data.

Effect of Aluminum Nitride (AlN) Addition on Wear and Mechanical Properties of Al-Si Alloy Composites Fabricated by Stir Casting Process

2011 ◽  
Vol 462-463 ◽  
pp. 307-312 ◽  
Author(s):  
Mahamad Noor Wahab ◽  
Mariyam Jameelah Ghazali ◽  
Abdul Razak Daud
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Great Improvement ◽  
Casting Process ◽  
Stir Casting ◽  
Wear Behaviour ◽  
Weight Percentage ◽  
Reinforced Composite ◽  
Ductile Fractures ◽  
Metallic Compounds

The effect of AlN addition in Al-Si alloy composites on the mechanical properties and dry wear behaviour were studied using pre-selected parameter conditions. In this work, high purity of AlN powders with different weight percentage of 5, 7 and 10 were used as reinforced materials for the composites. Morphology of the reinforced composite indicated that both silicon grains and inter-metallic compounds were surrounded by the AlN particles. The presence of AlN in the Al-Si alloy showed a significant improvement in tensile properties in which 7wt% of AlN addition increased up to 25% compared to those of without any reinforcements. Fracture morphologies with small dimples, tear ridges and necking features indicated that ductile fractures had occurred on the Al-Si composites. At 25N load, alloys with 5wt% of AlN exhibited high wear resistances whereas at 70N, alloys with 10wt% of AlN showed a great improvement in wear resistance. SEM investigation also revealed that the presence of wear was also marked with prominent grooves, craters and scoring marks. Overall, alloys with 7wt% AlN addition possessed great improvement in hardness, tensile and wear resistance properties.

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