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Steel for heavy forgings - forging process Large ingots are required for smelting and forging large forgings. The single weight of large ingots ranges from 30 to several hundred tons. The larger the ingot is, the more serious the metallurgical defects such as segregation are. Therefore, the smelting requirements of steel for large forgings are very strict. In order to ensure the casting of extra large steel ingots, it is generally necessary to use more than two smelting furnaces for casting, so it is not necessary to increase the capacity of a single furnace and reduce the erosion of refractory…

In recent years, due to the requirements of environmental protection, the small cupola of most foundry enterprises has been replaced by the small medium frequency induction furnace. As the cupola uses coke and other fuels, metallurgical reaction occurs in the smelting process, while the electric furnace smelting is mainly alloy remelting, and the metallurgical reaction is not significant The process characteristic of smelting cast iron in electric furnace is that the undercooling degree of alloy increases after molten iron remelting, and the superheat temperature is higher, which brings new problems to the quality control of cast iron. After hot metal…

Process Diagram of Water Cooled Metal Mold Centrifugal Casting melting Add raw materials (scrap steel, pig iron, recycled materials, etc.) into the melting furnace (induction furnace or cupola) and adjust their composition. When the composition meets the process requirements, pour molten iron into the frequency conversion holding furnace for spheroidizing. If the sulfur content in molten iron exceeds the standard, desulfurization treatment shall be carried out first. Spheroidization When the composition and temperature of molten iron meet the process requirements, the spheroidizing agent is added to the molten iron to change the flake graphite in the molten iron into spherical…

1) Amorphous materials have low moisture absorption, and the water absorption of PPO is very low. However, the moisture will cause defects such as silver wire and bubble on the surface of the product. Therefore, the raw materials can be put in an 80~OOC oven and dried for 1-2 hours before use. 2) The molecular bonds of PPO are rigid, the glass transition temperature is high, and it is difficult to orient, but it is difficult to relax after forced orientation. Therefore, the residual internal stress in the product is relatively high, which generally requires post-processing. 3) PPO is an…

Metal Powder Injection Molding (MIM) is a new powder metallurgy near net shape forming technology that introduces modern plastic injection molding technology into the field of powder metallurgy. The basic technological process is as follows: first, the solid powder and organic binder are uniformly mixed, then granulated, injected into the mold cavity with an injection molding machine under the heating and plasticizing state (~150 ℃) for curing and forming, and then the binder in the forming blank is removed by chemical or thermal decomposition methods, and finally the final product is obtained through sintering and densification. Compared with the traditional…

High grade gray cast iron generally refers to gray cast iron above HT250. In the production process, it can be roughly divided into the following forms: one is inoculation cast iron; The other is alloy cast iron (rare earth gray cast iron is mainly introduced here). Now let's talk about my own views and understanding on the two kinds of high grade gray cast iron casting. 1、 Inoculated cast iron In gray cast iron, graphite exists in the form of flake, which seriously damages the properties of iron matrix. In order to improve the mechanical properties, the number of graphite…

Metal cutting machine tools (hereinafter referred to as machine tools) are a large number and a wide range of equipment. Their structural characteristics, machining accuracy, degree of automation, working conditions and operating environment conditions are very different, and they have different requirements for lubrication systems and lubricants used. 1、 Features and requirements of machine tool lubrication: 1. The main parts of machine tools are mostly typical mechanical parts, which are standardized, generalized and serialized. For example, the lubrication conditions of sliding bearings, rolling bearings, gears, worm gear pairs, rolling and sliding guides, screw drive pairs (screw nut pairs), clutches, hydraulic…

1. Check the drawing to confirm whether it is the first corner view or the third angle view, and confirm whether the bending direction is correct according to the drawing using the perspective drawing method. 2. Confirm whether the material and plate thickness are correct according to the drawing, inspect each bending dimension according to the drawing, and give priority to the tolerance dimension and hole to edge dimension. 3. Check whether the bending tool mark meets the product requirements. If the surface is not treated, A1 surface is not allowed to have defects such as indentation, indentation and scratch.…

What is spinning technology? It is also called metal spinning forming technology. It is a technology that makes the stress point go from point to line, from line to surface through rotation, and at the same time, gives a certain pressure in a certain direction to make the metal material deform and flow along this direction to form a certain shape. Here, metal materials must have plastic deformation or flow performance. Spinning is not equivalent to plastic deformation. It is a complex process integrating plastic deformation and flow deformation. It should be pointed out that the spinning technology is not…

High cutting speed and cutting precision are the main differences between CNC cutting machine and hand-held cutting and profiling cutting. Although the cutting speed of the CNC cutting machine is fast and the cutting accuracy is high, many customers find that the processing efficiency has not been improved much after they bought the CNC cutting machine. The main reason is that the users do not have a thorough understanding of the relevant knowledge of the CNC cutting machine and can not use it easily. What should new users pay attention to when using CNC cutting machine to effectively improve cutting…