I am a processing bearing material is cast steel, I want to know how his hardness, crisp, crisp, not like the past, broken.
The extension rate is much larger than the cast iron, is unlikely to collapse, the collapse of the past you no more than two may be; one is design of the basic dimensions of the bearing seat is too small (not enough strength), two foundry material or not did not give you the annealing (casting stress uniformity).As far as bearing housings are concerned, the Brinell hardness of HB is usually used to express more than 200. There should be a special measuring instrument for measuring the hardness of the workpiece. Can come to a conclusion.An experienced teacher with a hacksaw or file on the workpiece and scraping can probably determine the workpiece hardness can not be used to distinguish. But now the master is dead.
If you do not have a special appliance, you can only refer to experience:A. If heat treatment has been done, a surface oxide (reddish) on the surface has been found in the case of a normalized heat treatment (normalizing or tempering), and in this case the casting will not have any of the phenomena you are talking about. In addition, you can see whether the casting is overheated by observing the riser.Two. Generally, the casting will not be brittle unless the material of the casting is defective, such as S, P content or excessive C content.The brittle term you speak is that the elongation is small and has no direct relation to hardness.
What do you use for this kind of bearings? What's the working condition? Do not say clearly, the general bearing seat is cast iron many, unless you use the occasion is a special occasion, or have special requirements. Cast iron is cheaper than cast steel, easy to process and good in material stability, but the strength is almost worse than that of cast steel. Hardness is lower than that of cast steel. As to the brittleness, it depends on what material your cast steel is. Some cast steel is also very brittle. When the external force reaches a certain degree of bearing (for example, hammering with a hammer), it will be like a bearing, and that one will break.
