Following.

Mu Jingchi went to school as usual, and first went to Professor Tian's office to check the teaching plan with the professor.

Professor Tian has been teaching and educating people for a long time, and he has a very deep understanding of the course "Fundamentals of Materials Science", so he teaches Mu Jingchi from a strategic perspective.

"The Fundamentals of Materials Science course is attended by juniors who have already taken pre-foundation courses in mathematics, physics and chemistry in their freshman and sophomore years. So some of them involve computational analysis, and we don't need to be too detailed, leaving room for students to think for themselves. ”

"It's not that computational analysis isn't important, it's the opposite, it's very important, especially in mechanical analysis. But when we teach, in the third year of college, we have to start to develop students' ability to think proactively. ”

"Sometimes a good way to teach is just to point out the key points, and let the students go through the process on their own, and for them, the process in between is important. ”

"College teaching is not high school teaching, high school teaching is result-based teaching, and college teaching is heuristic process teaching. Sometimes, the content of the textbook is not necessarily correct, and it may be true at our time, but it may be overturned in the future. ”

This is especially important. ”

Mu Jingchi nodded, "I understand, Professor." ”

"Classes start next Monday, and you're ready. "That's all that needs to be said, the rest is the real teaching practice.

After finishing his teaching plan work, Mu Jingchi went to the Materials Research Building to continue his experiments, and also managed graduate students such as Ai Xiaosheng.

At this time, the graduate students were busy with experimental projects, but they were a little excited. Seeing Mu Jingchi coming, he looked at him with a burning gaze.

Such a considerate person in charge of graduate students, what a good person!

Obviously, the four graduate students were impressed by the end of work at half past five yesterday.

"Dr. Mu, are you free?"

While the equipment was running and waiting for data, a graduate student wearing glasses came over and asked Mu Jingchi cautiously.

"Free for now, something?"

The glasses graduate student nodded, "I would like to ask you to help me look at my own project." ”

Mu Jingchi's expression softened a little, revealing a slightly interested look, "Take it for me to see." ”

Apparently, the glasses graduate student had already prepared, and quickly ran out of the laboratory, and came over with a document in less than two minutes. Graduate students can't expect Mu Jingchi to go to the computer mailbox to receive it, and printing it out is the best choice.

Effect of Hot and Cold Deformation Treatment on Microstructure and Mechanical Properties of Ultra-low Carbon Medium Manganese Quenched Zone Tempered Steel

This is the name of the subject, at a glance Mu Jingchi felt that this topic was good, for these high-quality master's students in Huaqing, it was not up to the same as just the right subject research.

Mu Jingchi looked at it carefully and carefully, this is the responsibility of the graduate students, so he will not be perfunctory.

This eyewear graduate student may have been influenced by Mu Jingchi, and his research direction is also starting from automotive materials, but the research is on steel materials.

For manufacturing and safety reasons, the automotive steel is mainly concentrated in low-alloy medium-manganese steels with a combination of high strength, high plasticity and high toughness.

Plasticity is generally due to the influence of phase transition-induced plasticity and twin-induced plasticity of a large number of fine austenites. However, as an austenitic stabilizing element, the addition of carbon is limited, which can affect welding properties and cause plastic instability.

The current effective solution is to use a combination of nanoprecipitation hardening and phase change-induced plasticity to improve the strength and ductility of the alloy at a low cost.

The direction of the graduate students is to quench and temper the cold-rolled and hot-rolled steel of ultra-low-carbon medium manganese, study its microstructure and mechanical properties, and analyze and evaluate the respective roles of the internal nano-precipitation hardening and phase transformation-induced plasticity.

After reading this project design, Mu Jingchi nodded without a trace in his heart.

"Yes, both in terms of direction and design, it's not bad. Mu Jingchi affirmed the graduate students who do things for themselves, "But after the real project starts, it may not be as good as expected, so be mentally prepared." ”

"If you have a problem that you can't solve, you can come to me. ”

In the course of the experiment, there will always be some problems, which is inevitable, and sometimes it is inexplicable that the cause cannot be found. I don't know why the experiment failed, so I had to be mentally prepared.

Those hidden national material projects, projects with extremely high requirements for materials, are basically piled up by failure again and again. Maybe five or ten years will end in failure, if the psychological adjustment ability is a little worse, it will not be able to reach the relevant height at all, and it will be crushed by failure again and again.

"Yes, Dr. Mu. ”

A smile curled into the corner of the glasses graduate student's mouth, and he was very grateful for Mu Jingchi's words.

For empirical scientific research such as material scientific research, if there is a big guy with it, it can avoid many detours and it is easier to produce results.

The graduate student withdrew from the lab and immediately passed the news on to the other three graduate students, who visited him again.

Mu Jingchi naturally did not refuse.

Effect of Hydrogen Content on the Transformation of Tensile Fracture Failure Mechanism of 304 Austenitic Stainless Steel Welded Joints

Perhaps it was discussed with other graduate students, but the graduate student who laughed and had two dimples also chose steel-based materials.

During the processing or service process of the material, hydrogen atoms will be adsorbed on the metal surface, and penetrate, diffuse, and accumulate in some parts, resulting in a significant reduction in macroscopic plasticity and strength, that is, hydrogen embrittlement.

In recent years, due to the rapid development of the hydrogen energy industry, higher requirements have been put forward for the performance of hydrogen-resistant materials serving in the hydrogen environment.

300 series austenitic stainless steels are widely used as load-bearing components in hydrogen-containing environments due to their high resistance to hydrogen embrittlement and weldability.

Compared to austenite, hydrogen has a higher diffusion coefficient but lower solubility in α martensitic, therefore, the presence of martensitic in stainless steel increases the hydrogen embrittlement sensitivity of the material.

In addition, the stress of substable austenitic stainless steel from austenite to α martensite will induce martensite transformation during plastic deformation, and suffer from serious hydrogen embrittlement.

Many studies have found that hydrogen has a significant effect on stress-induced martensitic transition and fracture mechanisms. During welding, complex thermal cycling gives the weld metal special microstructures that affect hydrogen transport and result in a high hydrogen embrittlement sensitivity to the weld metal.

Therefore, it is particularly important to study the effect of hydrogen on the properties and failure mechanisms of austenitic stainless steel welded joints to understand the hydrogen embrittlement of austenitic stainless steels.

"There's no problem, don't worry about doing it boldly!" Mu Jingchi's tone was full of encouragement.

Professor Yang Wenwu and Professor Tian Bo supported Mu Jingchi in the back, and Mu Jingchi also stood behind these research societies to support them.

Only by inheriting in this way will material scientific research get better and better.