1.原材料缺陷
1. raw material defects

如鋼錠或鋼材存在殘余的縮孔、氣泡、疏松、夾雜等，可能導致鍛件開裂。冶金原因引起的鍛造裂紋，其高倍檢驗特征，經常是伴有大量的氧化物井蓋鋼模具 U型槽模具 天津水處理設備 檢查井鋼模具 保定公司注冊 u型槽模具 流水槽模具 、硫化物、硅酸鹽等夾雜。高碳、高合金鋼的原材料，容易存在嚴重的碳化物等第二相偏析，如果鍛造時未能予以擊碎并使其分布均勻，則會降低鍛件的力學性能，熱處理時可能導致鍛件開裂或畸變。原材料表面若存在刮傷、結疤、折疊、發裂都會給鍛件帶來缺陷。因此，在模鍛生產中必須對原材料進行檢驗。
If there are residual shrinkage holes, bubbles, loose and inclusions in ingot or steel, cracking may occur. The high strength inspection characteristics of forging cracks caused by metallurgical reasons are often accompanied by a large number of inclusions of oxides, sulphides and silicates. The raw materials of high carbon and high alloy steel are easy to have serious second phase segregation of carbides. If the forging is not broken and distributed evenly, the mechanical properties of the forgings will be reduced, and the cracking or distortion of the forgings may be caused by heat treatment. Scratching, scarring, folding and cracking will result in defects on the surface of the raw material. Therefore, raw materials must be inspected in die forging.