Improve Wear Resistance And Reliability Of Machinery Castings
Improve wear resistance and reliability of Machinery Castings
In order to properly machine tool casting material to high strength, high stiffness development, and further improve the wear resistance of the machine tool and the use of reliability, the development and application of a number of new materials in recent years:
(1), HT300 high-strength pregnant cast iron. Machinery Castings The addition of iron liquid from 1450 ℃ to 1470 ~ 1520 ℃, the proportion of scrap in the charge composition (adding 40% ~ 50%), the use of C-si, Ca-Ba and CaMnSi-Bi inoculants, etc. Technical measures, in the CE ≥ 3.5% under the conditions of access to HT350 grades.
(2), high Si / C gray cast iron. Under the condition of carbon equivalent CF = 3.4% ~ 3.8%, the addition of scrap is increased, the Si / C ratio is increased from 0.4 ~ 0.5 to 0.7 ~ 0.8, the temperature of molten iron is increased to above 1450 ℃, the tensile strength can be increased by 20 ~ 30mpa. E0 value also increased, the casting has a small tendency to deformation. However, for thicker castings such as machine tools, increasing the Si / C value increases the ferrite content at the thick section, but reduces the strength. At this time should be added Cr, Ca, Sb and Sn and other alloying elements, improve the machine at the cross section of pearlite content, Machinery Castings reduce the hardness of the cross-section, increase the accuracy of machine tools and stability.
Domestic test using vibration aging, reduce and reduce the residual stress within the Machinery Castings. Its effect on residual stress. Due to the increase of the elastic modulus of the material after vibration, the anti - load capacity of the casting increases, the anti - static capacity is increased by 30%, and the anti - load capacity is increased by 100% ~ 300%.