High manganese steel intermediate frequency furnace smelting operation specification

High manganese steel intermediate frequency furnace smelting operation specification
1 the scope of application of this process is only applicable to the intermediate frequency furnace smelting Gao Menggang (D Spec 10315AA-AC P operation
2 process preparation
2.1 preparation: after high temperature calcination of scrap and, high carbon ferromanganese, ferrosilicon Si75, drying through water slag refining agent and covering agent, graphite carbon agent and hair
Thermal insulating agent; an essential tool for smelting, sampling spoon and slush and after roasting to glowing red pouring package. Deoxidizer: rare earth silicon alloy, CASI groats
2.2 the furnace examined the extent of the damage, timely in conjunction with the relevant personnel were on-site consultation, and according to the furnace repair process specification timely lining repair,
Repair and overhaul work;
2.3 check the operation of the parts of the electrical control panel, check the work of the transfer of records, if there are problems should be handled in a timely manner with the relevant personnel.
2.4 understanding of the daily casting daily required to complete the number of castings, material, single weight and type of shell drying time, temperature and other data;
% 2.5 chemical composition of high manganese steel: C 1.05 ~ 1.35 Mn 11 ~ 14 Si = 1 P = 0.07, S = 0.05
Mechanical properties: tensile strength more than 50000Psi (345MPa)
The elongation rate (4D%) = 1
The permeability of u is less than or equal to 1.03 (100 Austria 20 DEG C)
The resistivity is greater than or equal to 68 * 10-6.Cm (20 DEG C).
List of ingredients: Scrap 400KG FeMn70C7 65KG high carbon ferromanganese medium carbon ferromanganese FeMn75C2 23 KG 0.31 KG particle ink stone
Si75+ silicon 3.86KG particles of rare earth ferrosilicon calcium (3 ~ 10mm) 5KG for scrap components yet, this ingredient is for reference only
3 process
3.1 feeding: adding slag making materials and scrap, plugged. Melts as well as feeding.
3.1 power melting: the first 60% of the power to run properly, and then increase the power to heat up the melting.
3.2 ground material poking, ground observation, prevent the burden of scaffolding material, caused the penetration, caused by the leak accident.
3.3 when feeding to prevent adding closed tubular furnace charge, should pay attention to its smooth exhaust and prevent the heat explosion and destroy;
3.4 scrap melting after the cleaning, adding high carbon ferromanganese and medium carbon ferromanganese, melting in the rear can be with ferrosilicon (including rare earth ferrosilicon for deoxidation. Due to deoxy deoxy agent exothermic reaction, temperature rise quickly, should immediately sampling and analysis of chemical composition.
3.5 in front of the stove analysis during melting into the refining stage. The operator should reduce the furnace power, to about 60% of operation, to prevent excessive rising temperature, at the same time, strengthen the change of slag and the slag surface diffusion deoxidation refining work, to prevent slag oxidative blackening., but also to prevent surface slag, caused a large number of elements loss.
3.6 analysis results after the announcement, melting into the last period of adjustment, calculation and weighing accurate fill and alloy should be in the slag surface voids in poke into and pay attention to the melting, prevent complement and elements are slag bonding and loss. C to control in less than or equal to 1.4%, the better Mn Mn is more than or equal to 12.5% P P < 0.06% sulfur s less than or equal to 0.05%.
3.7 after adding element end, melting into the last full power, rapid warming state. After the heating immediately granulated calcium silicon deoxidation eventually. Amount decided on site, to prevent excessive levels of silicon.
3.8 in final deoxidation. At this time the glowing of pouring package before entering the furnace should wait state. Shell mold assembly has been completed, at the same time be pouring state, heat preservation
Warm material is also in standby.
4 Casting of alloy
4.1 in order to obtain the excellent performance of the equiaxed grains, high manganese steel casting temperature should be as low as possible, generally 5 to 8 minutes after pouring is arranged in the Bao Zhongjing.
4.2 cleaning package nozzle at the scum and dust, prepare slag measures, pouring to fast, slow, fast, slightly pause, then Bu Chong riser. Timely fill riser rush,
Can use the impact of the casting profile is more complete, and effectively improve the feeding effect of riser.
4.3 to strengthen the mold cavity into the model of the movement of the alloy liquid, so that the first crystallization of the solidification of the columnar crystal, favorable to obtain such as axial crystal.
Manganese iron powder according to the weight of 1 ~ 1.5% of the casting, and gradually added to the gate cup or the opening of the channel to add to the liquid flow, increase External crystal core, grain refinement, equiaxed grains. But to prevent manganese content exceed the standard.
4.4 in order to prevent the production of wrinkles groove, or produce slag, cracks and other defects, mold cavity temperature as high as possible.
4.5 in the surface of the larger riser cover enough of the heat insulation material is also a measure to improve the feeding effect.
4.6 in order to prevent chemical sand defects of high manganese steel, sand and steel contact should be on the part of corundum coating, and drying to be poured.
5 safety and precautions
5.1 before casting finishing market to clean up the channel, is the safe production of the essential link.
5.2 participate in prevention work clothes and protective glasses is a measure of safety in production
5.3 high manganese steel best use of rare earth silicon alloy for final deoxidation, because rare earth can improve the morphology of inclusions buckle distribution, improve the toughness and wear resistance of the steel, method: Use of 0.5 ~ 1mm to rust bags of rare earth alloy and fixed in the rod tip, after fully baked, in before tapping 1 minute into the furnace alloy liquid in the bottom were free end Deoxy). If there is no rare earth alloy, also available silicon calcium alloy crushed after baking instead of aluminum deoxidation, modification and grain refinement. The current method and theProcess requirements differ.