Category: Manufacturing Technology knowledge

The casting grain coarseness refers to the defect that shows the grain structure is too coarse to be suitable for application when the machinist or the fracture inspection is carried out. This kind of coarse grain structure may be distributed throughout the whole casting, or may occur locally. In essence, coarse grain defect is a metallurgical defect. Based on many years of production practice and referring to relevant information, the author talks about the causes of coarse grain defects in castings and preventive measures. 1 Casting structure and process design (1) If the section difference of the casting is too…

1. Corner melting When cutting the corner of the sheet steel at a reduced speed, the laser will melt the corner due to overheating. A small radius is generated at the corner to maintain high speed laser cutting and avoid overheating and melting of steel plates when cutting corners, so as to obtain good cutting quality, reduce cutting time and improve productivity. 2. Part spacing In general, when cutting thick plates and hot plates, the distance between parts should be large, because the heat of thick plate hot plates has a great impact, and when cutting sharp corners and small…

During the processing of stainless steel parts, the deformation of parts caused by welding is often encountered. Part deformation is only a surface phenomenon. Due to the role of welding heat source, it is easy to overheat the weld metal and the welding heat affected area, which often leads to defects in the weld metal and the metal grains in the heat affected area. In addition, in order to prevent and eliminate the adverse effects of welding on parts, it is necessary to control the temperature of parts and wait for parts to cool down for the next weld welding…

1. Incorrect knife tip angle When grinding the turning tool, the tool tip angle is incorrect, that is, the included angle between the projection of the two cutting edges of the turning tool on the base surface is inconsistent with the tooth profile angle of the machined thread, resulting in the incorrect angle of the machined thread. Solution: When grinding the turning tool, an angle ruler or sample plate must be used to detect the correct tooth profile angle. The method is: parallel the sample plate or angle ruler to the front of the turning tool, and then check with…

Special attention shall be paid to the following points during the use of aluminum alloy die casting die: 1. Cleaning the parting surface of the mold is very troublesome and easy to ignore. If the boss has a high starting point and buys a good mold, it will be much easier to work. If the mold quality is not good, there will inevitably be flash or dirt on the parting surface of the mold during production. The operator should often clean these parts and equip a small shovel at any time. If the flash is not removed in time, the…

Screw threads are classified according to the number of spiral grooves on the thread in addition to the section shape. The thread with one spiral groove is called single head thread. Threads with more than two spiral grooves are called multi head threads. The distance between two adjacent spiral grooves on the thread is called pitch. The distance along the spiral groove is called lead. The relationship between lead and pitch can be expressed by the following formula L = t  ×  Where, L - thread lead (mm), N - Number of thread heads, T - thread pitch (mm). When…

Nowadays, in more and more industrial applications, lasers have been seen as an alternative solution for welding plastics/composites directly to metals. This non-contact processing method provides the highest process flexibility. At present, one of the driving factors in the automotive industry is how to make lighter cars without increasing costs or causing damage or impact on performance, quality and safety. For seat structures, this mainly includes the use of thin, higher strength steel. In recent years, mixed material structures have also been widely studied. This also applies to metal only hybrid structures and component structures made of metal/plastic composites. The…

1 Salt bath heat treatment Company A is located in Sendai, Miyagi Prefecture, Japan, about 300 km from Tokyo. The company mainly produces a variety of mechanical blades, the longest of which is more than 5m. Blade materials mainly include high-speed steel, hard alloy and alloy tool steel. Heat treatment heating furnace includes salt bath furnace, vacuum furnace, box type multi-purpose furnace, large protective atmosphere furnace, large gas carburizing furnace, etc. There are two sets of salt bath furnaces being produced on site: one is Cr12MoV steel tool quenching line, and the other is high-speed steel or base steel quenching…

How does the laser cutting machine technology deal with the problem of burrs? When some customers use the laser cutting machine to process sheet metal, the effect of the workpiece cut is very unsatisfactory, and there are many burrs. Then many customers begin to doubt the quality of the laser cutting machine products, but it is not. During the cutting process of metal laser cutting machine, due to improper operation and technical problems, the processed materials will not produce burrs. Burrs only occur in metal cutting, and there is no burr problem in non-metallic cutting. How are burrs produced? In…

1、 Workpiece over cutting: reason: 1. The tool strength is not too long or too small, causing the tool to snap. 2. Improper operation by the operator. 3. Uneven cutting allowance. (For example, 0.5 for the side of the curved surface and 0.15 for the bottom) 4. Improper cutting parameters (such as too large tolerance, SF setting too fast, etc.). improve: 1. The principle of using a knife: big or small, short or long. 2. Add the corner cleaning procedure, and leave the allowance as uniform as possible (the allowance on the side and bottom shall be consistent). 3. Reasonably…