Due to the different types, the cutting performance of
stainless steel plates is also different, and the problems that will appear in reaming are also different. For example, when reaming austenitic stainless steel such as 1Cr18Ni9Ti and stainless steel resistant to concentrated nitric acid, the main problems will be The problem of reamer wear; when reaming martensitic stainless steel such as 2Cr13, it is mainly difficult to ensure the roughness and dimensional accuracy of the reaming hole.
Therefore, in order to avoid the occurrence of the above problems, the following aspects should be paid attention to.
The first is to choose the appropriate reamer and reaming amount, which are the key points to ensure that the reaming can be carried out smoothly.
The second is to improve the quality of the pre-processing process, which can effectively avoid the occurrence of grooves, ellipses, polygons, tapers or bell mouths, waist drum shapes, axis line bending, deflection, etc. in the pre-processing holes.
In addition, it is necessary to keep the hardness of the stainless steel workpiece at a moderate level, especially for 2Cr13 martensitic stainless steel, the hardness after quenching and tempering treatment is more suitable below HRC28.
Before processing, the reamer and the workpiece need to be installed correctly. The reamer must be installed correctly, and the axis of the reamer must be consistent with the axis of the pre-machined hole of the stainless steel workpiece, so as to ensure that each tooth can be cut evenly.
It is also necessary to select a suitable cutting fluid during processing, which can effectively solve the problem of chip adhesion in stainless steel reaming holes, and enable it to remove chips smoothly, so as to reduce the surface roughness of the hole and enhance the durability of the tool. Usually it is better to use vulcanized oil. If 10%-20% CCl4 is added to vulcanized oil or 20%-30% CCl4 is added to lard, the surface roughness can be significantly reduced. Because CCl4 is harmful to the human body, a mixture of 85%-90% vulcanized oil and 10%-15% kerosene can be used. When the diameter of the reamer is large, internal cooling can be used.
During the reaming process, carefully observe and strictly check the runout of the cutter teeth, because this is the key point to obtain uniform reaming. During the reaming process, also pay attention to the shape of the chips, because the reaming allowance is small, the chips will be in the form of foil rolls or very short spiral coils. If the chips are of different sizes, some are in the form of fine powder, and some are in the form of small blocks, indicating that the reaming is uneven. If the chip is in the shape of a strip of spring, it indicates that the reaming allowance is too large. If the swarf is needle-like and flake-like, the reamer is dull. In addition, it is necessary to avoid the occurrence of chip clogging, and if it occurs, it must be cleaned up in time.
