Option 33
1. Select carbon steel for making drills. Assign a thermal mode
Processing, describe the essence of the transformations that occur, the structure and properties of the instrument.
2. Copies should have minimal deformation and high wear resistance.
Surface layer with a hardness of 750 ... 1000 HV. For their manufacture, steel 38ХВФЮА is chosen.
Specify the composition and determine the steel group for its intended use. Assign and justify the thermal regime
And chemical-thermal treatment, explaining the effect of doping on transformations,
Occurring at all stages of processing this steel. Describe the structure and properties of steel after
Processing.
3. For the production of a permanent magnet with a section of 50x50 mm, the alloy EX9K15 is chosen.
Decode the composition and specify the alloy group for the intended purpose. Assign a thermal mode
And describe the structure and properties after treatment. Explain why in this case
You can not use U12 carbon steel.
4. As a material for casting liners of bearings of sliding the alloy
B16. Specify the composition and determine the alloy group for the intended purpose. Describe the microstructure of the alloy
And the basic requirements for alloys of this group.
5. Thermoplastic plastics, their features and scope. Give examples
The most important thermoplastics.