GOST 11964 fraction - 81 - application, selection, production
Fraction is made two &ndash types; cast (fraction steel DSL, fraction pig-iron DChL) and chipped (steel DSK, pig-iron DChK).
the Cast fraction (DSL fraction, DChL fraction) has spherical shape.
Cast fraction - numbers of fraction 0,3 - 3,6mm are issued according to GOST 11964 - 81, fraction with a diameter of 4 - 7 mm - according to specifications.
Fraction steel cast (DSL fraction) and the fraction pig-iron cast (DChL fraction), is issued the sizes from 0,3 to 7 mm.
the Chipped fraction (DSK fraction, DChK fraction) has the form of the wrong polyhedron, it turns out by split of spherical fraction.
Chipped fraction is issued with a diameter of 0,3 - 2,2 mm according to GOST 11964 - 81.
The technical fraction (steel, pig-iron) is applied in many industries.
Generally it is used in foundry productions when cleaning products of scale, prigar, the remains of forming mix etc.
Also apply fraction at preparation of a surface before drawing coverings, to it clear products of firm pollutants of various origin, in fraction strengthen metal, use as ballast etc. of
In application of technical fraction there is a number of advantages:
* safety for environment and service personnel - there are no pollutants and all waste goes to secondary processing.
* usability - all parameters are visually controlled and easily adjusted,
economic efficiency - proceeding from the previous points, and also considering relative simplicity of the equipment for bead-blasting processing, fast learning ability of personnel, a possibility of fast start of process and repeated use of the material, you save time and money.
Choice of fraction.
Technical fraction happens pig-iron and steel (DCh - fraction pig-iron, DS - the fraction steel), also fraction is subdivided on cast and chipped (L - cast, K - chipped).
also improve Fraction, that is additional heat treatment which increases service life of fraction and improves its physical properties (At &ndash is carried out; improved).
The fraction is subdivided into fractions, diameter of grains from 0,3 - 0,5mm to 5,0mm.
At the choice of an optimum abrasive take the following criteria into account:
* the required quality of a surface;
* cleaning productivity;
* expense and cost of an abrasive;
* design and cost of the equipment;
Purpose of steel and pig-iron fraction:
* drobemetny and bead-blasting cleaning of castings, forgings, hire;
* superficial hardening of hard loaded details like shaft, springs, springs, cogwheels;
* preparation of a surface under painting;
* removal of a rust from metal designs;
* cabin of marble and granite;
* cleaning of coppers of power plants;
* ballast filling of capacities (the ballast fraction differs in the largest size).
Steel fraction in comparison with pig-iron has also following advantages:
* has a wide range of application;
* gives to the processed surface more uniform roughness;
* forms much less dust;
* increases labor productivity;
* reduces wear of the equipment;
* gives economy of the electric power and air due to decrease in time of cleaning;
* reduces an abrasive expense;
* operational costs.
Pig-iron fraction firmer, steel more plastic.
Cyclic firmness - this parameter is not regulated by state standard specification and standards, but in determination of total cost of processing of material plays a crucial role.
Cyclic firmness of DSL - 280 - 300th cycle;
Cyclic firmness of DSLU - 450 - 600th cycle;
Cyclic firmness of DChL - 85 - 200th cycle.
* Cleaning of forming mixes.
* Cleaning of scale.
* Preparation of a surface.
* Hardening of a surface.
Density of all numbers and types of fraction, except chopped, has to be not less than 7200 kg/m3.
the Hardness of pig-iron cast fraction (DChL fraction) makes 545... 830 HV.
the Hardness of the pig-iron cast improved fraction (DChLU fraction) makes 455... 580 HV.
Fraction steel cast (DSL fraction), fraction steel chipped (DSK fraction), fraction steel cast improved (DSLU fraction), fraction steel chipped improved (DSKU fraction) is produced two ranges of hardness:
365... 545 HV and 545... 830 HV.