Supervisor of master's dissertation is Konarev V.G.

RESEARCH OF STRUCTURE AND PROPERTIES OF TOOTHED FIXATIVE ELEMENTS
 

 A substantial problem is death gear-wheels, new methods for their production are therefore developed, consolidating and final treatment. To promote quality and longevity and cut prime costs making of gear-wheels, it is necessary to apply in industry progressive technological processes on all operations, including purveying.

Firmness of gear-wheels in a great deal depends on the sequence of operations of final heat treatment mechanical and. The technological process of making of gear-wheels and his sequence is determined by the degree of exactness, parameters of hooking, overall sizes, easily soiled steel, method of chemistry - thermal treatment, serial of production and other.

Tooth’s of wheels must possess high enough by durability, hardness, ability to resist to the abrasion and other properties providing reliable work of gearing at least its sizes and mass. Therefore gear-wheels make mainly from alloy steel carbon and with maintenance of carbon 0,1-0,6% (for large billows-cog-wheels to 0,9%) with chemistry - thermal treatment a heat or, considerably rarer from cast-iron and non-metal materials - plastics. Worm-wheels are made from copper alloys (bronzes, composition-metals).

One of principal reasons of breakage of Tooth’s can be the overload. In this case there is an identical structure in a fracture. Breakage of Tooth’s at foundation is caused also by the fatigue of metal at the repeated tensions of bend from the high loadings. This type of destructions is characterized by two areas: own tireless destruction with a fine-grained or smoothed out brilliant surface and area of static destruction with a krupnokrystallycheskoy structure.

Gear-wheels which make on KHMF MMK to them were explored in this work. Yl'ycha. On a factory it is supplied with a rental, the preliminary purveyances are after cut on the saw КМ915. After the preliminary cutting the purveyances are passed in a smithy, where the final purveyance is forged on the hammer М415А. The purveyance for a gear-wheel is processed on a screw-cutter 1М63, Tooth’s of narezayutsya on Tooth’s - the milling machine 5А326.

Subject the got gear-wheel to subsequent heat treatment (to tempering and vacation) in the stove of the chamber type SSHO 6.83/10.After heat treatment a gear-wheel is finally processed under a landing place on the lathe 1К62.

By the got gear-wheel there is the clamp of detail on a lathe 1М63 for its subsequent treatment. In the process of work znakoperemennye tensions, smynayuschye and destroying Tooth’s, operate on a gear-wheel, that is the reason of fall of the processed detail from the clamps of lathe.

On the transversal section of gear-wheel with the blasted tooth hardness was measured on hardness Rokvella on a scale With, mikrohardness tooth and cavity between Tooth’s is measured. On the transversal section of gear-wheel shlyfy were done. On the Neofot 21 microscope the microstructure of edge, middles and grounds of tooth, and also microstructure of cavity, was exposed. On the Metam 2Р microscope the pictures of microstructure were done, at the increase х100 and х500.

As a gear-wheel works on a wear, he must have high hardness of Tooth’s (order 50HRC), which is provided by the structure of martensyta. In this case distributing of hardness on a tooth is uneven, the value of hardness on the average makes 38HRC, distributing of mikrohardness on the section of tooth and cavity is also uneven. The microstructure of Tooth’s and cavity consists of beynyta and corns of ferryta, a superficial layer obezuglerozhen.

Thus, it is possible to do a conclusion, that the heat treatment of gear-wheel conducted on a factory is done not right.

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