En-GJL-250 Grey Cast Iron Machine Tool Bed

Machine tools bed is generally made of grey iron En-GJL-250 material, and the main machine tool castings include: machine tool bed castings, machine tool work bench castings, machine tool column castings, machine tool beam castings, machine tool ram castings and other key castings. Which machines contain these castings?

For example: key castings of gantry milling machine, key castings of gantry planer, key castings of large vertical lathes, key castings of CNC gantry milling machine, key components of CNC vertical lathes, etc. The structure of boring machine and CNC boring machine is a single column, so there is no beam casting. Why machine tool bed is all made of grey iron En-GJL-250?

Among all castings, the physical properties and production costs of grey iron EN-GJL-250 castings can well meet the performance requirements of machine tools. What are the main physical properties of grey iron En-GJL-250?, and what is the specific content?

First of all, the physical properties include: tensile strength, hardness, wear resistance, corrosion resistance, etc.

The tensile strength value is Rm(MPa)=250, and the hardness value is (RH=1)209HB, and the above data are measured according to the diameter of 30mm test rod.HT250 machine castings are grey iron castings of pearlite type, and their density is about 6.8-7.3g/cm³. The values of the five major metal elements are carbon C: 3.16-3.30, silicon Si: 1.79-1.93, manganese Mn: 0.89-1.04, sulfur S: 0.094-0.125, and phosphorus P: 0.12-0.17. If the hardness value of the guide rail surface of the machine tool bed needs to be increased, the surface hardness of En-GJL-250 cast iron can reach HTC60 after quenching.

The economic cost of En-GJL-250 grey cast iron machine tool bed is also in the lower middle range of all castings. Based on economic costs and excellent physical performance. Therefore, machine tool bed generally use En-GJL-250 grey cast iron castings.