Jong-Ho Shin

• Doosan Corporation

The effect of Nb on austenite grain growth kinetics was investigated in 10Cr-3Co-2W martensitic heat-resistant steel under various tempering conditions (temperature and time). The results demonstrate that Nb effectively refines the austenite grain size; this result is attributed to the combined effect of Nb atom solute drag effect and pinning effec...

High-nitrogen austenitic steel (HNS) cold-rolled with a reduction rate of 25% was subjected to an investigation of the effect of annealing temperature on microstructural evolution, tensile properties and the variation in fracture surface morphology. In cold-rolled HNS, matrix recovery occurred at an annealing temperature of 600 °C, and recrystalliz...

In this study, we conducted preliminary research with the objective of leveraging artificial intelligence to optimize the efficiency and safety of the entire Ambient Air Vaporizer (AAV) system for LNG (Liquid Natural Gas). By analyzing a year-long dataset of real operational data, we identified key variables that significantly influence the outlet...

High-Mn lightweight steel, Fe-0.9C-29Mn-8Al, was manufactured using steelmaking, ingot-making, forging, and rolling processes. After the final rolling process, a typical austenite single phase was observed on all sides of the thick plate. The microstructural changes after annealing and aging heat-treatments were observed, using optical and transmis...

The effects of the heat treatment and the specimen orientation relative to the building platform on the microstructural evolution and mechanical properties were investigated in an IN718 alloy built by the selective laser melting process. The specimens were built in the perpendicular and the parallel directions to the building platform. Optical micr...

This study examined the influence of partial replacement of Co with Cu on isothermal transformation kinetics in 10Cr‐based heat‐resistant steels. Two kinds of heat‐resistant steels, having similar chemical compositions except for Co and Cu contents, were prepared and isothermally heat‐treated at 710 ∽ 790 oC up to 240 h after austenitization. Durin...

The effects of heat treatment conditions on the microstructures and mechanical properties of Ta and Ti added reduced activation ferritic/martensitic (TaTi-RAFM) steel were investigated in this study. The authors attempted to control the precipitation of MX particles and M23C6 carbide, which critically affects the mechanical properties of RAFM steel...

In this study, the resistance to pitting corrosion of Fe-18Cr-9Mn-5.5Ni-0.3(C + N) austenitic stainless steel γ-SSs (in wt%) with different C/(C + N) ratios (0.02, 0.29, and 0.60) was evaluated. It was found to be difficult to form a γ-matrix without precipitation, because the Cr23C6 precipitation rate in the γ-SSs with the C/(C + N) value of 0.60...

We investigated the effect of κ-carbide precipitates on the strain hardening behavior of aged Fe–Mn-Al-C alloys by microstructure analysis. The κ-carbides-strengthened Fe–Mn-Al-C alloys exhibited a superior strength-ductility balance enabled by the recovery of the strain hardening rate. To understand the relation between the κ-carbides and strain h...

The effects of the cooling rate, after solution heat treatment, on the microstructures and mechanical properties of Fe-22Mn-8Al-0.8C-0.02Nb (low carbon) and Fe-20Mn-8Al-1.1C-0.1Nb (high carbon) light-weight steels were systematically investigated. The cooling process was controlled to achieve six different cooling rates, ranging from -0.016 to -465...

This study explored the transformation of austenite to ferrite and precipitation behavior during the isothermal annealing of heat-resistant steel based on Fe-9Cr-1.5Mo-1.25Co-0.1C-0.2 V-0.05Nb (wt%). For this purpose, the samples used here were initially reheated to the full austenitization temperature and thereafter directly annealed at 710 °C and...

In many manufacturing or service industries, there exists maximum allowable tardiness for orders, according to purchase contracts between the customers and suppliers. Customers may cancel their orders and request compensation for damages, for breach of contract, when the delivery time is expected to exceed maximum allowable tardiness, whereas they...

Serrated flow in high-Mn lightweight steel was examined in the temperature range of 25–425°C with strain rates of 3.33 × 10⁻⁴, 3.33 × 10⁻³ and 3.33 × 10⁻² s⁻¹. Transmission electron microscopy (TEM) analysis showed a bowing dislocation line caused by an interaction between dislocations and the solute in the solid-solution. The activation energy of...

A mold steel for plastic injection was subjected to low cycle fatigue (LCF) tests at temperatures of 25, 200, and 250 °C. LCF tests were carried out at a total strain amplitude (Δεt/2) from 0.004 to 0.012 under a constant strain rate of 0.01 s–1. Transmission electron microscope images showed that cyclic loading accelerated dislocation recovery as...

High-Mn lightweight steel, Fe-0.9C-30Mn-8Al, was subjected to systematic examination to investigate the effects of aging heat-treatment on mechanical properties and tensile behavior as a function of test temperature from 25 to 425 °C and strain rate of 3.33 × 10⁻⁴, 3.33 × 10⁻³ and 3.33 × 10⁻² s⁻¹. Peak in the flow stress, plateau of yield strength...

Order-lot matching is the process of assigning items in lots being processed in the make-to-order production system to meet the due dates of the orders. In this study, an order-lot matching problem (OLMP) is considered to minimize the total tardiness of orders with different due dates. In the OLMP considered in this study, we need to not only deter...

To gain the fundamental understanding of deformation mechanisms in an aluminum-containing austenitic high-Mn steel (Fe-32Mn-8.9Al-0.78 C (wt.%)), in-situ straining transmission electron microscopy (TEM) analysis is conducted. The in-situ observation during the deformation demonstrates that the plastic deformation is accommodated by the pronounced p...

The hot workability of 9Cr-1.5Mo-1.25Co-VNb ferritic-martensitic steel was investigated through hot compression tests using Gleeble simulator over a temperature range of 1223 K (950 °C) to 1573 K (1300 °C) and strain rates of 0.001 to 0.5 per second. Through an analysis of the stress(σ)–strain(ε) curves obtained during the hot compression tests, a...

Martensitic transformation (MT), constituting an essential part of deformation scenario, plays a key role in plasticity and thermoelasticity of face-centered cubic (fcc) materials. Despite being an area of intense research, discrepancies remain about the essential parameter dictating nucleation of hexagonal close-packed (hcp) martensite and about t...

The effects of Mn and C content on the age hardening of Fe–Mn–Al–C lightweight steels, which have austenitic or duplex (austenite and ferrite) microstructures, were investigated. An increase in Mn content induced a delay of the age hardening that is caused by the formation of intra-granular κ-carbides. In order to interpret the effect of Mn content...

The parking problem is a very important issue in city life because many citizens waste a large amount of energy and time trying to find suitable parking lots. To resolve this problem, various intelligent parking guidance systems have been introduced. However, the method of operating an intelligent parking guidance system remains in the infant stage...

The constantly increasing number of cars in the megacities is causing severe parking problems. To resolve this problem, many cities adopt parking guidance system as a part of intelligent transportation system (ITS). However, the current parking guidance system stays in its infant stage since the obtainable information is limited. To enhance parking...

The offshore plant equipment usually has a long life cycle. During its O&M (Operation and Maintenance) phase, since the accidental occurrence of offshore plant equipment causes catastrophic damage, it is necessary to make more efforts for managing critical offshore equipment. Nowadays, due to the emerging ICTs (Information Communication Technologie...

Over the last decade, a rapid development of internet, wireless mobile telecommunication, and product identification technologies make whole product life cycle visible and controllable, which can improve several operational issues over the whole product life cycle: product design improvement, predictive maintenance, rational decision on end-of-life...

In the case of a high-valuable asset, the Operation and Maintenance (O&M) phase requires heavy charges and more efforts than the installation (construction) phase, because it has long usage life and any accident of an asset during this period causes catastrophic damage to an industry. Recently, with the advent of emerging Information Communication...

The O&M (Operation and Maintenance) phase of offshore plants with a long life cycle requires heavy charges and more efforts than the construction phase, and the occurrence of an accident of an offshore plant causes catastrophic damage. So previous studies have focused on design for reliability, and recently many studies have dealt with a maintenanc...

The effects of aging temperature on the microstructural evolution and the tensile behavior of precipitation hardened martensitic steel were investigated. Microscopic analysis using transmission electron microscope (TEM) was combined with the microstructural analysis using the synchrotron X-ray diffraction (XRD) to characterize the microstructural e...

Parking problem becomes one of major issues in the city transportation management since the spatial resource of a city is limited and the parking cost is expensive. Lots of cars on the road should spend unnecessary time and consume energy during searching for parking due to limited parking space. To cope with these limitations and give more intelli...

The effects of microstructure evolution with different amount of cold compression on the mechanical behavior were investigated in high nitrogen austenitic stainless steel. Maximum tensile strength and 0.2% yield strength was increased with the increase of cold compression percent. Twin intersection in two different crystallographic orientations was...

Thanks to recent technology related to product monitoring and data communication, it is now possible for a company to gather various kinds of product usage data during its operation in a ubiquitous way. However, the application of the newly gathered data is still vague and immature. If the data is transformed into appropriate information or knowled...

The hot workability of a nitrogen-alloyed Fe–18Mn–18Cr–N austenitic stainless steel was investigated through hot compression tests using a Gleeble simulator in a temperature range of 700–1100 °C and at strain rates of 0.01–5 s−1. From stress(σ)–strain(ε) curves obtained in the hot compression tests, a processing map was established to estimate the...

The effects of nitrogen content, cold working, and stress relief treatment on the mechanical properties of high-nitrogen 18Mn-18Cr austenitic steels with different nitrogen content are investigated with respect to the specimen direction and location. The yield and tensile strengths usually increased with increasing nitrogen content and cold working...

In general, it is difficult to select a satisfactory product concept because the information in the early stage of design process is subjective, qualitative, and even uncertain to design engineers. The correlations among engineering characteristics for a product concept also increase the complexity of conceptual design. Moreover, it becomes importa...