Outlining the symposium program.

Chairman: Thank you. Now I would like to open the discussion. Please feel free to ask questions and make comments. Time is rather short, so I would invite everyone to be brief and keep to the point. Please identify yourselves before asking your questions.

V.P.: Vladimir Podshibyakin, I represent the Chelyabinsk Technical University, Russia. Mr. Smirnov, have you developed any computer programs?

V.S.: Yes, we have. The mathematical model, which describes the process of braking with ABS, was later realized on a computer as a program.

Chairman:Are there any more questions? ... Yes, please.

J.P.:Julia Poslamovskaya from Samara Technical University. I’d like to ask Mr. Smirnov about his present research and the results expected.

V.S.: Now I develop the methods of increasing the durability of front suspension element. I hope that the result of my work will be the development of a new method of front suspension lever checking or a new construction of the lever.

Chairman: OK. Thank you, Mr. Smirnov for your answers. Now I’d like to give the floor to our second reporter Konstantin Belyaev from St. Petersburg.

K. Belyaev: Thank you, Mr. Chairman. I am glad to have this opportunity to present my paper at this plenary session. The purpose of this paper is to present a new class of vehicles – walking machines. The problem of designing walking machines attracts much attention today. One of perspective directions of research work in this field is developing the simplest plantigrade vehicles. The walking machines designed at our department are of this type.

I would like to start by showing the video (shows the film). Here we see the transport walking machine which was designed in 1997. The machine consists of two walking supports like walking support for the sprinkling machine "Kuban" and a central frame. The machine has also its own isolated micro generating plant. This machine has statical stability that is multilegged machine. Walking machine can be divided into vehicles of profile practicability and vehicles of ground practicability.

We have tested the machine in a difficult region near the town Dubovka of the Volgograd region. The machine was able to overcome a swamp of 0.6 metres deep, a rise of 30 and an obstacles of 0,2 meters altitude. This work is sponcered by the Russian Fund of Basic Research.

The experimental research has allowed us to reveal a number of disadvantages, particularly the low speed of movement caused by imperfection of walking support, and also limited turning ability of the machine. At the same time, the high ground and profile practicability of machines and ecology have been proved. With this I would like to finish. If there are questions, I’ll be glad to answer them. Thank you.

Chairman: Thank you, Mr. Belyaev. I again invite the participants to ask questions. ... Yes, Mr. Smirnov, please.

V.S.: Mr. Belyaev, in what kind of ground can your walking machine be used?

K.B.: The vehicles of ground practicability can be used for moving on relatively flat terrain and on the soils with poor carrying layer such as sand, marshland and others. They can also move on the soils with ecologically injured layer for example tillage, tundra, permafrost.

Chairman: Any other questions? Yes, please, identify yourself.

J.B.:Julia Bogdanova from Ufa, Russia. What is the purpose of your work?

K.B.: The purpose of my work is perfection of walking support and the development of a new experimental sample with more perfect kinematics scheme of turn.

Chairman: Thank you very much. The question time is up. And now our third reporter, Julia Poslamovskaya from Samara. Please.

J. Poslamovskaya: Thank your Mr. Chairman. Dear colleges, I would like to start my report defining the actuality of my research. The topic of my paper is “Investigation of macrostructure‘s defects in the large steel ingots.” A large steel ingot is a semi-product out of which different hardware is obtained by means of forging or rolling methods. These things can be used in heavy machine building, shipbuilding, military and chemical industries. There are different kinds of products used in industries: guns, shafts, reactors, rotors of turbo generators, steam boilers and so on. (They are shown in Fig.1).

It is clear that the improvement of quality of these products and their mechanical properties are very important. These disadvantages may lead to catastrophic consequences and great losses in our economy (Fig 2 - Metallurgical products).

The purpose of my paper is to design new technologies or to modify the old ones which make it possible to diminish or eliminate these defects.

I carry out research on metallic models cut out of large steel ingots. In my experimental work I used different methods. The method of macro etching permitted us to discover macrodefects in steel ingots (It is seen as the light region in Fig 2). It is the metallic forging substance, which appeared in the ingot during the flooding time of metal into the casting form (Fig 2 - Macrodefects in steel ingot). The method of micro etching helped to analyze the microstructure of basic metal and metallic forging substance. The structure of basic metal is a homogeneous perlit-ferrit structure and metallic forging substance is heterogeneous one (It is presented in picture 3). The heterogeneous structure is formed by speeded cooling of small metal volumes. Fig. 3 (а, b) – Microstructure of steel 42CrMo4V:

а) basic metal with the fraction of metallic forging substance. ×200;

b) metallic forging substance. ×200

Metallographical and petrographical methods allowed me to investigate the composition of various impurities presented in steel (It is demonstrated in Figure 4) and clear up the causes of its formation.

Fig. 4 (а, b) – Impurities presented in the steel. 42CrMo4V.×50:

а – MgО∙Al₂O₃- 2FeO∙SiO₂, b – 2FeO∙SiO₂-2MnO∙SiO₂

Therefore the purpose of my research is to solve the problem of metal contamination caused by various impurities which lead to different defects in metal.The investigation of different impurities is very important practically, because they are found in steel and lead to the appearance of cracks during the crystallization or mechanical treatment ( Figure2). The obtained data showed that the cause of cracks is metallic forging substances formed on casting equipment (It is shown in Fig. 5 - Metallic forging substance on casting equipment).

In conclusion I would like to say the following. To eliminate defects in steel one should use high-temperature strength sands and keep the temperature rate and technology of casting. I hope the results of my research will be useful in future.

Chairman: Right, that was our last speaker. So any questions or comments?

N.K.: Natalia Keibal from Volzhsky Polytechnic Institute, Russia. I’d like to stress that the problem under discussion attracts much attention. The development of methods, which decrease metal contamination, is an important problem because it is connected with solving ecological problems.

Chairman: Thank you, Ms. Keibal for your comment. Any more questions? Yes, please, Mr. Belyaev.