Towards A Computational Intelligence Framework in Steel Product Quality and Cost Control

Steel is a fundamental raw material for all industries. It can be widely used in vari-ous fields, including construction, bridges, ships, containers, medical devices and cars. However, the production process of iron and steel is very perplexing, which consists of four processes: ironmaking, steelmaking, continuous casting and rolling. It is also extremely complicated to control the quality of steel during the full manufacturing pro-cess. Therefore, the quality control of steel is considered as a huge challenge for the whole steel industry. This thesis studies the quality control, taking the case of Nanjing Iron and Steel Group, and then provides new approaches for quality analysis, manage-ment and control of the industry. At present, Nanjing Iron and Steel Group has established a quality management and control system, which oversees many systems involved in the steel manufacturing. It poses a high statistical requirement for business professionals, resulting in a limited use of the system. A lot of data of quality has been collected in each system. At present, all systems mainly pay attention to the processing and analysis of the data after the manufacturing process, and the quality problems of the products are mainly tested by sampling-experimental method. This method cannot detect product quality or predict in advance the hidden quality issues in a timely manner. In the quality control system, the responsibilities and functions of different information systems involved are intricate. Each information system is merely responsible for storing the data of its corresponding functions. Hence, the data in each information system is relatively isolated, forming a data island. The iron and steel production process belongs to the process industry. The data in multiple information systems can be combined to analyze and predict the quality of products in depth and provide an early warning alert. Therefore, it is necessary to introduce new product quality control methods in the steel industry. With the waves of industry 4.0 and intelligent manufacturing, intelligent technology has also been in-troduced in the field of quality control to improve the competitiveness of the iron and steel enterprises in the industry. Applying intelligent technology can generate accurate quality analysis and optimal prediction results based on the data distributed in the fac-tory and determine the online adjustment of the production process. This not only gives rise to the product quality control, but is also beneficial to in the reduction of product costs. Inspired from this, this paper provide in-depth discussion in three chapters: (1) For scrap steel to be used as raw material, how to use artificial intelligence algorithms to evaluate its quality grade is studied in chapter 3; (2) the probability that the longi-tudinal crack occurs on the surface of continuous casting slab is studied in chapter 4;(3) The prediction of mechanical properties of finished steel plate in chapter 5. All these 3 chapters will serve as the technical support of quality control in iron and steel production

Advanced Turbine Technology Applications Project (ATTAP)

This report is the fourth in a series of Annual Technical Summary Reports for the Advanced Turbine Technology Applications Project (ATTAP). This report covers plans and progress on ceramics development for commercial automotive applications over the period 1 Jan. - 31 Dec. 1991. Project effort conducted under this contract is part of the DOE Gas Turbine Highway Vehicle System program. This program is directed to provide the U.S. automotive industry the high-risk, long-range technology necessary to produce gas turbine engines for automobiles with reduced fuel consumption, reduced environmental impact, and a decreased reliance on scarce materials and resources. The program is oriented toward developing the high-risk technology of ceramic structural component design and fabrication, such that industry can carry this technology forward to production in the 1990s. The ATTAP test bed engine, carried over from the previous AGT101 project, is being used for verification testing of the durability of next-generation ceramic components, and their suitability for service at Reference Powertrain Design conditions. This document reports the technical effort conducted by GAPD and the ATTAP subcontractors during the fourth year of the project. Topics covered include ceramic processing definition and refinement, design improvements to the ATTAP test bed engine and test rigs and the methodology development of ceramic impact and fracture mechanisms. Appendices include reports by ATTAP subcontractors in the development of silicon nitride and silicon carbide families of materials and processes

Block 2 SRM conceptual design studies. Volume 1, Book 2: Preliminary development and verification plan

Activities that will be conducted in support of the development and verification of the Block 2 Solid Rocket Motor (SRM) are described. Development includes design, fabrication, processing, and testing activities in which the results are fed back into the project. Verification includes analytical and test activities which demonstrate SRM component/subassembly/assembly capability to perform its intended function. The management organization responsible for formulating and implementing the verification program is introduced. It also identifies the controls which will monitor and track the verification program. Integral with the design and certification of the SRM are other pieces of equipment used in transportation, handling, and testing which influence the reliability and maintainability of the SRM configuration. The certification of this equipment is also discussed

Evaluation of the formability properties of nitrogen alloyed metastable austenitic stainless steels

Bibliography: pages 92-95.This study examines the formability of an AISI 301 based metastable austenitic stainless steel, in which nitrogen partially substitutes nickel. In order to understand the formability of the experimental alloys, the tensile behaviour of the alloys is characterised. The tensile properties of metastable austenitic stainless steels are governed by austenite stability which is related to alloy composition and test temperature. At certain alloy compositions, transformation induced plasticity (TRIP) occurs. TRIP depends on the manner in which deformation induced martensite forms in the steels. Incipient necking is resisted if the martensite forms gradually and selectively, preventing propagation of micronecks and microcracks. Tensile tests performed from -5 to 100°C were used to study the effect of TRIP on the ductility of these alloys and optimum tensile properties were obtained at room temperature. In addition, the effect of copper on TRIP and subsequently formability were ascertained using copper alloyed stainless steels. Important stretch formability parameters were obtained from the tensile test which is an intrinsic formability test. TRIP results in improved formability of metastable austenitic stainless steels, and a simulative Engelhardt test was performed to ascertain the effect of TRIP on drawability of the test alloys. It was found that alloys with TRIP characteristics exhibited good drawability and in all cases the test alloys had better limiting drawing ratios than AISI 304 stainless steel. Delayed cracking occurred in alloys with more than 0.2 percent nitrogen content and a low austenite stability, probably as a result of embrittlement of the deformation induced martensite by nitrogen. A study of the cavitation erosion of the test alloys was initiated because it is known that TRIP enhances cavitation erosion resistance in stainless steels. Results indicate that the metastable test alloys demonstrate superior erosion resistance when compared with the stable experimental alloys. Cavitation induced martensite was found in metastable alloys using x-ray diffraction

Advanced Powder Metallurgy Technologies

Powder metallurgy is a group of advanced processes used for the synthesis, processing, and shaping of various kinds of materials. Initially inspired by ceramics processing, the methodology comprising the production of a powder and its transformation to a compact solid product has attracted attention since the end of World War II. At present, many technologies are availabe for powder production (e.g., gas atomization of the melt, chemical reduction, milling, and mechanical alloying) and its consolidation (e.g., pressing and sintering, hot isostatic pressing, and spark plasma sintering). The most promising methods can achieve an ultra-fine or nano-grained powder structure, and preserve it during consolidation. Among these methods, mechanical alloying and spark plasma sintering play a key role. This book places special focus on advances in mechanical alloying, spark plasma sintering, and self-propagating high-temperature synthesis methods, as well as on the role of these processes in the development of new materials

The Effect of Cooling Rate on the Microstructure Configuration of Continuously Cast Steel Slabs

This research work is another step for increasing the efficiency and productivity of the steel making process by enhancing both quality and quantity of the steel produced by the Continuous Casting process. When steels cool from a high temperature, austenite transforms into other phase configurations according to the austenite composition and cooling rate. As result of phase transformation, the steel crystal structure and, consequently, both the shape and the lattice parameter of the unit cell, change. These changes may introduce dilatational strains into the microstructure, which result in the creation of residual stress concentration zones within the microstructure. These stress concentration zones are vulnerable regions to the formation of microcracks or growth of the flaws in these regions. The main objective of this dissertation is to develop a method to define the optimum cooling rate for cooling continuously as-cast steel on industrial level. An FEM algorithm developed with the ANSYS codes is introduced in this dissertation to simulate the cooling of as-cast steel from any temperature below the solidification temperature. The algorithm is capable of being customized to simulate the thermodynamic behavior of as-cast steel microstructure with any chemical composition and any casting geometry imposed to desired cooling method. The phase transformation simulations were based on the CCT diagram and, therefore, they were quasi-real models. The models predict, analytically, the generation of the stress concentration regions due to the thermodynamic strains during cooling a sample from the austenite temperature range with different cooling rates. Another series of FEM models presented in this dissertation and post non-destructive tests (NDT) ultrasonic image analysis tests suggested in this work, can be used in the discussion of the effect of the cooling rate on the altering of the soundness of the tested steel. A combination of the suggested FEM algorithm and post image processing of NDT ultrasonic images along with laboratory cooling experiments and microstructural analysis provide a guideline to find the cooling rate for each grade of steel in the casting steel industry. Results of JMATPRO software also are deployed to increase the accuracy of the experimental set up and to obtain the required input data to run the proposed numerical algorithm cooling simulation

Active thermography for the investigation of corrosion in steel surfaces

The present work aims at developing an experimental methodology for the analysis of corrosion phenomena of steel surfaces by means of Active Thermography (AT), in reflexion configuration (RC). The peculiarity of this AT approach consists in exciting by means of a laser source the sound surface of the specimens and acquiring the thermal signal on the same surface, instead of the corroded one: the thermal signal is then composed by the reflection of the thermal wave reflected by the corroded surface. This procedure aims at investigating internal corroded surfaces like in vessels, piping, carters etc. Thermal tests were performed in Step Heating and Lock-In conditions, by varying excitation parameters (power, time, number of pulse, ….) to improve the experimental set up. Surface thermal profiles were acquired by an IR thermocamera and means of salt spray testing; at set time intervals the specimens were investigated by means of AT. Each duration corresponded to a surface damage entity and to a variation in the thermal response. Thermal responses of corroded specimens were related to the corresponding corrosion level, referring to a reference specimen without corrosion. The entity of corrosion was also verified by a metallographic optical microscope to measure the thickness variation of the specimens

Superalloy Metallurgy a Gleeble Study of Environmental Fracture in Inconel 601

At temperatures above 0.5 Tm and in aggressive atmospheres predicting alloy performance is particularly challenging. Nickel alloys used in regimes where microstructure and properties are altered dynamically present unique requirements. Exposure may alter properties with unexpected early failure. The Gleeble is a valuable tool for investigation and simulation of thermo-mechanical properties of an alloy in various regimes up to the threshold of melting. In this study, four regimes of temperature and strain rate were simulated in an argon atmosphere to both investigate and document normal and abnormal failure modes. Commercial Inconel 601 was tested in selected regimes and in two treatments (as received and strain aged). Next two exposed conditions (TEOS and Hydride) were tested. Slow strain-rate and high temperature produced brittle intergranular fracture. Exposure at elevated temperature to process gases reduced both strength and ductility in both TEOS and Hydride. TEOS exposure reduced reduction in area in the alloy significantly more than the Hydride exposure

Quality control and improvement of the aluminum alloy castings for the next generation of engine block cast components.

This research focuses on the quality control and improvement of the W319 aluminum alloy engine blocks produced at the NEMAK Windsor Aluminum Plant (WAP). The present WAP Quality Control (QC) system was critically evaluated using the cause and effect diagram and therefore, a novel Plant Wide Quality Control (PWQC) system is proposed. This new QC system presents novel tools for off line as well as on line quality control. The off line tool uses heating curve analysis for the grading of the ingot suppliers. The on line tool utilizes Tukey control charts of the Thermal Analysis (TA) parameters for statistical process control. An Artificial Neural Network (ANN) model has also been developed for the on-line prediction and control of the Silicon Modification Level (SiML). The student t-statistical analysis has shown that even small scale variations in the Fe and Mn levels significantly affect the shrink porosity level of the 3.0L V6 engine block bulkhead. When the Fe and Mn levels are closer to their upper specification limits (0.4 wt.% and 0.3wt.%, respectively), the probability of low bulkhead shrink porosity is as high as 0.73. Elevated levels of Sn (∼0.04 wt.%) and Pb (∼0.03 wt.%) were found to lower the Brinell Hardness (HB) of the V6 bulkhead after the Thermal Sand Removal (TSR) and Artificial Aging (AA) processes. Therefore, Sn and Pb levels must be kept below 0.0050 wt.% and 0.02 wt.%, respectively, to satisfy the bulkhead HB requirements. The Cosworth electromagnetic pump reliability studies have indicated that the life of the pump has increased from 19,505 castings to 43,904 castings (225% increase) after the implementation of preventive maintenance. The optimum preventive maintenance period of the pump was calculated to be 43,000 castings. The solution treatment parameters (temperature and time) of the Novel Solution Treatment during the Solidification (NSTS) Process were optimized using ANN and the Simulated Annealing (SA) algorithm. The optimal NSTS process (516°C and 66 minutes) would significantly reduce the present Thermal Sand Removal (TSR) time (4 hours) and would avoid the problem of incipient melting without sacrificing the mechanical properties. In order to improve the cast component characteristics and to lower the alloy price, a new alloy, Al 332, (Si=10.5 wt.% & Cu=2 wt.%) was developed by optimizing the Si and Cu levels of 3XX Al alloys as a replacement for the W319 alloy. The predicted as cast characteristics of the new alloy were found to satisfy the requirements of Ford engineering specification WSE-M2A-151-A2/A4.* *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation).Dept. of Industrial and Manufacturing Systems Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .F735. Source: Dissertation Abstracts International, Volume: 66-11, Section: B, page: 6201. Thesis (Ph.D.)--University of Windsor (Canada), 2005