The Literary Life of a Science Leader

Chapter 75 Subject Review, Steel Materials

The next day.

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 "Basic Materials Science", so he taught Mu Jingchi the teaching method from a high-level perspective.

"Those who take the 'Basic Materials Science' course are all juniors. They have already taken the basic courses of mathematics, physics and chemistry in their freshman and sophomore years. So some of them involve calculation and analysis. We don't need Too detailed, leaving room for students to think for themselves.”

"It's not that computational analysis is not important. On the contrary, computational analysis is very important, especially in mechanical analysis. But when we are teaching, students should start to cultivate their active analytical thinking ability when they are in their junior year."

"Sometimes a good teaching method only needs to point out the key points, and let the students complete this process by themselves. For them, the intermediate process is the most important."

"University teaching is not high school teaching, high school teaching is result-based teaching, and college teaching is heuristic process teaching. Sometimes, the content in the textbook is not necessarily correct. It may be correct at this time, but it may be in the future. These contents will be overturned."

"This is especially important."

Mu Jingchi nodded, "I understand, Professor."

"The class will start next Monday, and you should be ready." That's pretty much all that needs to be said, and the rest is the real teaching practice.

After finishing his teaching plan work, Mu Jingchi went to the Caiyan Building to continue his experiments, and at the same time managed the graduate students like Ai Xiaosheng.

The postgraduate students are busy with experimental projects at this time, which is a bit exciting.Seeing Mu Jingchi approaching, he looked at him with burning eyes.

Such a thoughtful person in charge who considers graduate students, good man!

Obviously yesterday's 05:30 off work made these four graduate students look at each other with admiration.

"Doctor Mu, are you free?"

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

"I'm free for now, what's up?"

The glasses graduate student nodded, "I would like to ask you to read my own project."

Mu Jingchi's expression softened a little, showing a slightly interested look, "Bring it to me to have a look."

Obviously, the glasses graduate student was well prepared. He quickly ran out of the laboratory and brought out a document in less than 2 minutes.It is impossible for a graduate student to expect Mu Jingchi to go to the computer mailbox to receive it. Printing it out is the best option.

"Effect of hot and cold deformation treatment on the microstructure and mechanical properties of ultra-low carbon medium manganese quenched zone tempered steel"

This is the name of the project. Looking at Mu Jingchi at a glance, he feels that this project is good. For these talented postgraduate students in Huaqing, it is just a good project research.

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

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

Considering manufacturing and safety, the steel used in the automotive field is mainly concentrated in the low-alloy medium-manganese steel series with a combination of high strength, high plasticity and high toughness.

Plasticity is generally mainly derived from the influence of transformation-induced plasticity and twin-induced plasticity of a large number of fine austenites.However, as an austenite stabilizing element, the addition of carbon is limited, and carbon can affect weldability and cause plastic instability.

The current effective solution is to use the combination of nano-precipitation hardening and phase transformation-induced plasticity to simultaneously improve the strength and ductility of the alloy at low cost.

The direction of the glasses graduate students is to quench and temper the ultra-low carbon medium manganese cold-rolled and hot-rolled steels in different regions, study their microstructure and mechanical properties, and study the respective effects of the intrinsic nano-precipitation hardening and phase transformation-induced plasticity. analysis and evaluation.

After reading this project design, Mu Jingchi nodded silently.

"Not bad, whether it is in terms of direction selection or design, it is not bad." Mu Jingchi affirmed the postgraduate who worked for himself, "However, after the real project starts, it may not be as good as expected, so do a certain amount of work. Mentally prepare."

"If you have any problems that you really can't solve, you can come to me."

In the course of the experiment, some problems will always be encountered, which is inevitable, and sometimes the reason cannot be found for no reason.I don't know why the experiment failed, so you must be mentally prepared.

Those secret national material projects, projects with extremely high requirements for materials, are basically piled up after repeated failures.Maybe it will end in failure for five or ten years. If the mental adjustment ability is not good enough, you will not be able to reach the relevant heights at all, and you will be overwhelmed by repeated failures.

"Okay, Dr. Mu."

The corner of the glasses graduate's mouth curved into a smile, and he was very grateful for Mu Jingchi's words.

For empirical scientific research such as material research, if there are big bosses to lead, you can avoid a lot of detours, and it is easier to produce results.

The glasses graduate student quit the laboratory, and immediately passed the matter to the other three graduate students, so another graduate student came to visit.

Mu Jingchi naturally did not refuse.

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

Perhaps after discussing with other graduate students, this graduate student who has two dimples when he smiles also chooses steel-based materials.

During the processing or service of materials, hydrogen atoms will be adsorbed on the metal surface, and penetrate, diffuse, and gather in certain parts, resulting in a significant decrease 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 placed on the performance of hydrogen-resistant materials serving in hydrogen environments.

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

Compared with austenite, the diffusion coefficient of hydrogen in α-martensite is higher but the solubility is lower. Therefore, the presence of martensite in stainless steel will increase the susceptibility of the material to hydrogen embrittlement.

Furthermore, metastable austenitic stainless steel will undergo stress-induced martensite transformation from austenite to α martensite during plastic deformation, and suffer from severe hydrogen embrittlement.

Many studies have found that hydrogen has a significant effect on the stress-induced martensitic transformation and fracture mechanism.During the welding process, complex thermal cycles cause the weld metal to have special microstructures that affect hydrogen transport and lead to a high susceptibility to hydrogen embrittlement in 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 steel.

"No problem, do it with confidence!" Mu Jingchi's tone was full of encouragement.

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

Only if this inheritance continues, materials research will get better and better.

　Thank you to the readers for the reward, and continue to ask for recommendation votes every day!
　　
　
(End of this chapter)