Casting
Release date:2015-4-21 17:23:53 Source:Original site
In the high-energy impact working conditions, the scope of application of high-manganese steel and ultra-high manganese steel castings are bright. Many foundries, steel castings for the production of such a lack of necessary knowledge. Now for a brief description of the specific operation, for producers reference.
Chemical Composition
High manganese steel in accordance with national standards are divided into five grades, the main difference is that the carbon content, which ranges from 0.75% -1.45%. By the impact of large, low carbon content. Manganese content between 11.0% -14.0%, usually not less than 13%. Ultra-high manganese steel is no national standard, but should be greater than 18% manganese content. Low silicon content on the impact toughness greater impact, it should take the lower limit to no more than 0.5% is appropriate. Phosphorus sulfur is a basic requirement, due to the high content of natural manganese play desulfurization effect, it reduced phosphorus is the most important thing, trying to make phosphorus less than 0.07%. Chromium is to improve the wear resistance, generally about 2.0%.
Charging
Into the furnace material is determined by the chemical composition. The main charge is a high-quality carbon steel (or ingots), high-carbon ferromanganese, medium carbon ferromanganese, high-carbon ferrochrome and high manganese steel back charge. Here to remind that the people think that as long as the chemical composition of the right, you can go back to charge more. This person is harmful. The reason why some plants in poor product quality, all out of this. Not only high-manganese steel, high manganese steel, all metal castings, can never use too much scrap, back charge should not exceed 25%. So, back to how the excess charge? As long as the waste to a minimum, it will not charge the excess return.
Melting
Here emphatically stresses feeding order, regardless IF furnace or electric arc furnace melting, smelting always the first carbon steel, and various types of ferromanganese alloys and other precious materials, to divide repeatedly, each time a small amount into the furnace, precious element in the final added to reduce the burning. Slug should be smaller, with 50-80mm appropriate. After melting clean, temperature reaches 1580-1600 ℃, should deoxy, dehydrogenation, nitrogen, aluminum wire can be used, the material can also be used Si-Ca alloy or SiC, etc. The deoxidizer certain pressure to the depths of the furnace. This time with the metal surface coating agent Gaiyan cut off the outside air. Also sedation period, the oxide inclusions have sufficient time to float. However, many companies, only the aluminum wire or aluminum scrap, then sprinkle on the metal surface, do not add coverage, would not go to waste! In the meantime, in a timely manner with carbon ferromanganese to adjust the content of manganese and carbon.
Released before the molten steel, the ladle baking to over 400 ℃ is very necessary. Baked with a variety of trace elements during the V-Fe, Ti-Fe, rare earth and so do modification, is to make the necessary means to a crystalline refinement, it is critical that affect product performance.
Burden and modeling materials
To extend the furnace so as to distinguish between the steel and the lining of the property. Manganese is alkaline, of course, the choice of magnesia lining material. Ramming Lining To transposition operation cycle turns. Add a lining material is not too thick, each 80 cm is appropriate, low temperature for a long time to be completed pound baking. Such as increased productivity, the author suggested forming a crucible (Shenyang force must plant and Hengfeng plants are also finished products for sale), from demolition furnace pound pretend, not one hour, can be put into production, while forming a crucible for the anti-wear oven big benefit . Of course, the length of the operator to make a big furnace relationship. Many operators like throwing shot put athletes, three or four meters away from the charge into the furnace, the furnace is neither safe and injury orders should be placed next to the mouth charge preheating, then clip slowly charge Shun charge placed beside Preheat oven mouth, then slowly charge along with a clip into the furnace wall.
Modeling materials and coatings should also be consistent with the properties of liquid metal, or with ZTE materials (such as chromite sand, corundum, etc.). To get a refined crystalline mass, using the heat storage capacity of chromite sand is correct, especially LFC plant, use it to overcome the shortcomings of slow heat.
Previous:Nothing
Next:Regional characteristics of Chinese construction m
