High-manganese steel casting technology explanation

Under the working condition of high energy impact, the application range of high manganese steel and ultra-high manganese steel casting is broad. Many foundries lack the production of such steel castings. Make a brief explanation to specific operation now, provide for producer reference.
1 Chemical composition
High manganese steel is divided into 5 grades according to the national standards, the main difference is the carbon content, its range is 0.75% -1.45%. Heavy hit, low in carbon. The manganese content is between 11.0% -14.0%, and generally should not be less than 13%. There is no national standard for super high manganese steel, but the manganese content should be greater than 18%. The level of silicon content has a great impact on the impact toughness, so it is appropriate to take the lower limit to be no more than 0.5%. Low phosphorus and low sulfur is the most basic requirement, because the high manganese content naturally plays a desulfurization role, so phosphorus reduction is the most important, try to make phosphorus lower than 0.07%. Chromium is to improve the wear resistance, generally in about 2.0%.
2 Furnace material
The furnace material is determined by the chemical composition. The main furnace is high quality carbon steel (or ingot), high carbon iron manganese, medium carbon iron manganese, high carbon iron chrome and high manganese steel. A special reminder here is that people think that as long as the chemical composition is appropriate, it can be used back to the furnace material. This person is harmful. The reason why some factory product quality is not good, all out of this. Not only high manganese steel, ultra-high manganese steel, all metal castings, can not be used too much furnace material, furnace material should not exceed 25%. So, what about the excess return charge? As long as the waste is minimized, there will be no surplus.
3 Melt
Here focus on the order of feeding, whether with medium frequency furnace, or electric arc furnace smelting, always first smelting carbon steel, and all kinds of ferromanganese and other valuable alloy materials, to be divided into many times, each time a small amount into the furnace, precious elements in the last addition, to reduce the burn loss. The material block should be as small as possible, with 50-80mm is appropriate. After melting, when the furnace temperature reaches 1580-1600℃, deoxygenation, dehydrogenation, nitrogen removal, aluminum wire, Si-Ca alloy or SiC materials can also be used. Press the deoxygenation deep into the furnace. The metal liquid surface at this time with a covering agent to cut off the outside air. Also calm down for a period of time, so that oxides, inclusions have enough time to float. However, many enterprises, only aluminum wire and even aluminum chips, scattered on the metal liquid surface, and do not cover, is not a waste! During this period, medium carbon and iron manganese were used to adjust the content of manganese and carbon.
Before the steel, it is necessary to bake the package to more than 400℃. During the evaluation process, using V-Fe, Ti-Fe, rare earth and other trace elements is a necessary means to make the primary crystallization refinement, which is crucial to the product performance.
4 furnace charge and molding materials
To extend the furnace order, when to distinguish between the attributes of steel and furnace lining. Manganese steel is alkaline, furnace lining of course choose magnesium material. Mating furnace lining to be repeated transposition operation. Add furnace lining material is not too thick, about 80 cm each time is appropriate, tamping to low temperature for a long time. If the production efficiency is improved, the author suggests that the forming crucible (Shenyang Lide factory and Hengfeng factory both sell finished products), from the dismantling furnace tamping, not 1 hour, can be put into production, at the same time forming crucible is of great benefit to the anti-wear furnace. Of course, the length of the furnace order and the operator are large