SCHOOL OF ENGINEERING, TOHOKU UNIVERSITY Driving Force THE POWER TO MAKE TOMORROW INTERVIIEW REPORT
SCHOOL OF ENGINEERING, TOHOKU UNIVERSITY Driving Force THE POWER TO MAKE TOMORROW INTERVIIEW REPORT

I would like to continue
working as an engineer
in the field of
high-quality steel production.

Production Technology Section,
Shibukawa Plant
Daido Steel Co., Ltd.
Hitomi Noguchi REPORT #34

© School of Engineering, Tohoku University

Working on manufacturing
steel used under harsh
conditions by the aviation
and energy industries.

Airplanes are an indispensable means of transportation that connect domestic and international cities. The temperature at which gas combusts in a jet engine ranges from 1,500 to 1,600°c, with parts of the engine rotating more than 10,000 times a minute. Power plants are also necessary in supporting our daily lives. Their gas turbines operate at high temperatures exceeding a thousand degrees Celsius, and at high rotation speeds of thousands to tens of thousands of rotations per minute. Naturally, metal parts used under such harsh conditions require strict product standards and must be very safe.

Since its establishment more than 100 years ago, Daido Steel Co., Ltd. has continued to supply products in many industrial fields such as aviation and energy using its advanced technological capabilities. At its Shibukawa Plant in Shibukawa City, Gunma Prefecture, there is a female engineer who stands at the forefront of manufacturing. Her name is Hitomi Noguchi, a graduate of Tohoku University’s Graduate School of Engineering, Department of Materials Science, of the university’s School of Engineering’s Department of Materials Science and Engineering.

For four and a half years since she joined the company in April 2019, Ms. Noguchi has worked in the plant’s Melting Section, giving instructions regarding the melting process onsite, reducing manufacturing costs, and improving onsite safety. “When you want to stabilize the melting speed but it fluctuates, and the finished product does not meet the specifications set by the client, one of the important jobs of the Melting Section is to find optimal melting conditions in consultation with people in other departments such as the Production Technology Section and the Quality Assurance Section, and to give instructions to the plant," she says.

Aside from electric arc furnaces (EAF) that produce steel from iron scrap, the Shibukawa Plant is equipped with a wide variety of furnaces for steel manufacturing and specialized melting such as: vacuum induction melting (VIM) furnaces which melt and refine carefully selected materials in a vacuum; electro-slag remelting (ESR) furnaces which remelt using an inert gas to produce cleaner steel ingots; and vacuum arc remelting (VAR) furnaces which produce clean steel ingots with a low gas content through vacuum refining. Of these, Ms. Noguchi has mainly been working on the VIM, ESR, and VAR furnaces. “The most commonly used furnaces in the melting process are blast furnaces which produce iron from iron ore, and arc furnaces which melt scrap using heat from arc discharge. If quality is to be improved further, steel ingots must be made by melting in a vacuum or in an inert atmosphere. This is where ESR and VAR come in – these pieces of equipment remelt objects, which have been melted once, repeatedly the second and the third time. I find it very rewarding to make steel that’s used directly in products that must be highly reliable such as jet engine shafts and power plant turbine discs," she explains.

Stunned by the power
of gigantic arc furnaces
and dynamic melting.

Ms. Noguchi chose Daido Steel as her place of employment. She first encountered the company during her third year at a plant tour arranged by her university’s Department of Materials Science and Engineering. She says, “I visited various plants in the Nagoya area, and one of those plants was Daido Steel’s Chita Plant. There I was stunned to see a gigantic electric furnace – it was a 150-ton arc furnace. Unlike a blast furnace where molten steel comes out quietly, in an electric furnace, something like a thunderbolt is dropped on iron scrap, and a high voltage is applied to melt the scrap. The scrap melting amidst crackling, roaring sounds left a huge impression on me, and I thought it was so cool. I was very much impressed by the power of the equipment itself, and the dynamic melting process."

In the first year of her master’s program, she had an internship at Daido Steel. She spent two weeks at the research department where she was given the opportunity to conduct experiments on assigned subjects while interacting with people who were working onsite. “Unlike steel manufacturers whose products are mainly steel used in construction, Daido Steel excels at manufacturing steel used under harsh conditions, such as heat and corrosion-resistant materials. I was drawn to this specialty, which was why I chose to join the company. There are two main career paths for people with a background in materials, namely, manufacturing and research, and I have always liked manufacturing. I have always had a strong desire to work in a field that’s close to monozukuri (making things), a feeling which continues to this day," she says.

In October 2023, Ms. Noguchi left the Melting Section, which she was a part of since joining the company and was transferred to the Production Technology Section. The Production Technology Section conducts the detailed design of processes, from melting to the shipping of products. She says, “In the Melting Section, I mainly looked at the melting process, but since I was transferred, I have been conducting detailed studies to be able to meet standards from a wider perspective, such as forging that increases strength, testing tensile properties and corrosion, and others. I have also had more opportunities to talk directly with customers about their requests for certain properties and components. I am hoping that what I learned at university, such as the phase diagram of metals that shows how structure changes as temperature rises, will be even more useful to me now."

School of Engineering, Tohoku University Driving Force, The Power to Make Tomorrow. INTERVIIEW REPORT

My strength: communication skills in English cultivated through interactions with overseas students

Ms. Noguchi says that by being transferred to a new department, another skill she acquired during her university days became useful. In the Production Technology Section, she sometimes has meetings with foreign manufacturers in English, so this is where she demonstrates her communication skills in English. Before taking her graduate school entrance exam and job hunting, she studied for the TOEIC test on her own. She also says that another way she learned English which was also unique to Tohoku University was interacting with overseas students. She says, “In our lab, there were students from the Philippines and Mongolia. They hardly had any understanding of Japanese and were at a loss, so I translated the Japanese parts in our tests into English, and I created manuals in English on how to use our lab equipment for them. I also interacted with more senior overseas students from China and France, and we all went out to eat. The time I spent with them allowed me to naturally improve my English language skills."

At the School of Engineering, Ms. Noguchi was a member of the Metallurgical Process Engineering lab, where she researched the generation mechanism of aluminum dross. She chose this research subject because of her interest in environmental issues since her elementary and middle school years. She explains, “An unwanted compound formed when aluminum reacts with nitrogen and oxygen in the atmosphere, aluminum dross, which is generated during the recycling of aluminum, has the disadvantage of producing ammonia if left exposed to rain. Its processing is also expensive and not environmentally-friendly, which is why I chose its generation mechanism as my research subject. After graduating, I entered the Department of Materials Science at the Graduate School of Engineering and spent many productive hours at the Non-Equilibrium Materials Research Laboratory of the Institute for Materials Research researching “liquid metal dealloying" which is the selective elution of specific elements from alloys."

Many of the things around us are an aggregation of engineering knowledge that can be applied to other fields

Finding organic chemistry interesting in high school, Ms. Noguchi hoped to be admitted to the Department of Chemistry in the Faculty of Science, but after joining Tohoku University’s open campus day, she changed her mind and wanted to study at the Department of Materials Science and Engineering at the School of Engineering instead. She says, “On the open campus day, I went around both the Faculty of Science and the School of Engineering. There was a materials lab at the School of Engineering that was talking about “friction stir welding" (stirring and welding softened materials through frictional heat), and I found this welding technique very interesting. Even though I didn’t really like inorganic chemistry, I thought if I studied in a materials lab, I would surely be able to learn about organic chemistry too, so I changed my preferred department to the Department of Materials Science and Engineering at the School of Engineering. After being admitted to the university, I was shown various labs, and as I engaged in many experiments, I was drawn to the fun of learning about metals." Looking back at the 6 years of studying at Tohoku University, she explains the appeal of engineering, especially materials science, as such: “Even if it’s the same alloy, its structure changes depending on the temperature, and its properties also change when it is deformed. This is clearly different from other materials such as plastics, and this is what’s uniquely interesting about metals. With the abundance of metals and materials around us, I became very curious about things I didn’t really pay attention to up until high school, such as how such materials are made and how their atoms move."

Ms. Noguchi says that many of the things around us are “an aggregation of engineering knowledge." She says, “I think science is a field of study where we learn about the aspects of why phenomena occur. Meanwhile, engineering is the study of monozukuri, or making things. In terms of the scope, we can say that engineering is broader (than science). If you’re a high school student who’s debating between science and engineering, I think one solution is to choose the one with a broader scope. Engineering’s applicability to different fields is one of its appeals."

On her days off, she spends much of her time relaxing, but sometimes she goes to a bouldering gym nearby to work up a sweat. She has been rock climbing for more than 6 years. “I’ve been climbing and falling again and again," she laughs. We wonder what new heights she will climb to in her private and professional life