How Should Forgings Remove Defects?

Forgings in the production will inevitably appear some defects, some unpredictable, some can be avoided, so in forging processing to avoid defects as much as possible. Forgings common endo-hybrids are mainly sulphides, silicates, oxides and so on. Their quantity and composition in steel are related to the composition of steel, smelting quality, pouring process and deoxygenation method. The endogenous hybridization with high melting point, solidified before the base metal, crystallizes unobstructed, presents as a fixed angled shape, and the endogenous hybrid with lower melting point is mostly distributed along the crystal boundary due to the limitation of solidified metal. Sulphides and silicate components with better plasticity, when the ingots are forged and deformed, extend in the direction of the main deformation, and are striped.

The oxides and less plastic silicates are mixed and broken into small particles when forged and deformed, with a streptocular distribution. Small size, dispersion distribution of endoenomic hybrids, mostly micro-defects, less harmful. The mixing of large areas or dense cloud-like distribution constitutes a macro defect, which has a very bad effect on the use of forgings and can easily lead to serious failure accidents.

Foreign clamping refers to slag, protective slag, oxidation film, refractable materials and heterometallic blocks in mixed steel. Usually the foreign clamping is thicker, and the severe distribution will destroy the continuity of the steel and scrap it.

With the development of high parameters and large-scale machinery and equipment, more stringent requirements are put forward for the quality of large forgings, for which trace elements such as lead, palladium, tin, vanadium and arsenic need to be controlled in order to improve the toughening level of forgings. The general countermeasures for reducing the mixing in forgings are:

1, steel liquid vacuum treatment, off-furnace refining, control the quality of steel liquid;

2, clean pouring, to prevent foreign mixed pollution and foreign metals into;

3, reasonable forging deformation, improve the distribution of clutter.

From the above, it is also understood that some forgings produce defects, in the production to minimize the production of clutter, if the forgings have clutter, you can take some of the above countermeasures and measures to reduce, in the production of defects to eliminate defects in order to make forgings in the final completion, to achieve the best results.