After the forged knuckle is processed, it is qualified after the sample plate inspection, but after the heat treatment, it is found that the size of the knuckle traction table and the impact table changes greatly. Taking F-type forging knuckle as an example, the dimensional changes of traction table...
At present, F and CQ type knuckle are forged vertically and 16D type knuckle is forged horizontally, as shown in Figure 1. When vertical forging is used for forming, except for coupler knuckle pin hole and flag hole, machining allowance shall be reserved for all positions. When drawing the...
At present, the coupler knuckle used in the couplers of China’s railway freight cars is cast coupler knuckle. The cast coupler knuckle is an integral casting part with complex structure, and casting defects will inevitably occur in the casting process. The main failure forms of the cast coupler knuckle...
Forged coupler knuckle is an important part of the coupler and draft gear of freight cars. Forged coupler knuckle is an important part of the coupling of two freight cars. It connects the coupler and the center sill of the car body to transmit traction and braking force during...
Compared with similar foreign materials, the gap between China’s non quenched and tempered steel is as follows: 1) Poor quality of hot rolled products; 2) There is no certain control range for residual elements, resulting in great fluctuations in mechanical properties; 3) The chemical range specified in the standard...
It can be seen that the main differences between the quenched and tempered steel connecting rod and the non quenched and tempered steel connecting rod are as follows: 1) Microalloyed non quenched and tempered steel is to add V, Nb, Ti, B, N and other strengthening and refining ferrite...
The main failure mode of connecting rod is fatigue fracture. In order to keep the crankshaft in balance at high speed, the connecting rod quality tolerance is also required to be limited within a certain range. At the same time, the connecting rod body cannot be machined after die...
The process parameters of forging and quenching have a great influence on its strengthening effect. The main process parameters include: forging heating temperature, forging deformation, residence time after forging, forging quenching temperature, tempering after quenching with forging waste heat, etc. 1) Forging heating temperature (initial forging temperature): since the...
Application of forging heat quenching process: 1) The connecting rod produced by forging heat quenching has higher strength and toughness than that by ordinary heat treatment, especially the yield strength ratio of the connecting rod has been greatly improved. 2) The initial forging temperature of 45 steel shall not...
Compared with ordinary quenching and tempering, the hardness, tensile strength, elongation and impact value of forgings can be increased by 10%, 3-10%, 10-40% and 20-30% respectively. Generally, the increase of strength and hardness by ordinary heat treatment is always accompanied by the decrease of plasticity and toughness, while the...