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凤凰娱乐市东昊锻造有限公司

联系人:黄经理

电话:+639277308203

手机娱乐:+639277308203

地址:凤凰娱乐市南市区朱庄工业区

行业新闻
影响模锻件质量的主要因素
1.原材料缺陷
1. raw material defects

如钢锭或钢材存在残余的缩孔、气泡、疏松、夹杂等,可能导致锻件开裂。冶金原因引起的锻造裂纹,其高倍检验特征,经常是伴有大量的氧化物、硫化物、硅酸盐等夹杂。高碳、高合金钢的原材料,容易存在严重的碳化物等第二相偏析,如果锻造时未能予以击碎并使其分布均匀,则会降低锻件的力学性能,热处理时可能导致锻件开裂或畸变。原材料表面若存在刮伤、结疤、折叠、发裂都会给锻件带来缺陷。因此,在模锻生产中必须对原材料进行检验。
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.



2.加热规范
2. heating specification

锻造大型模锻件、合金钢模锻件时,若加热速度太快,内外层温差大,因温度应力和组织应力将导致中心部分裂纹。
When forging large mould forgings and alloy steel forgings, if the heating speed is too fast and the temperature difference between the inner and outer layers is large, the central part of the crack will be caused by the temperature stress and the tissue stress.

加热温度过高、保温时间较长引起轻微过热时,将产生有光泽、呈结晶状、沿晶断裂的粗晶断口。轻微过热的粗大晶粒可以通过退火或正火处理,经过重结晶加以纠正。严重过热时,将产生萘状断口或石状断口。萘状断口的特征是呈现鱼鳞状的亮点,穿晶断裂;萘状断口的产生原因,是粗大的奥氏体晶粒形成晶内织构,稳定性极高,在冷却过程中转变为铁素体时,仍会保留织构的特征。石状断口有明显粗晶,表面无金属光泽,色灰暗,沿晶断裂;石状断口的产生原因,是过热温度下非金属夹杂溶解度增大,而在冷却过程中,非金属夹杂又从过饱和的粗大奥氏体中析出,包围奥氏体晶粒形成脆性晶壳。过热严重的锻坯,其力学性能极差。萘状断口可以通过高温正火,消除晶内织构,而石状断口难以用热处理方法纠正,模锻件成形后,一旦发现石状断口就无可挽救。
When the heating temperature is too high and the holding time is longer, it will produce a coarse, crystalline fracture which is crystalline and intergranular. Slightly overheated coarse grains can be corrected by recrystallization or annealing or normalizing. When severe overheating occurs, a naphthalene fracture or a stone fracture will occur. The characteristics of naphthalene like fracture are the bright spot of fish and transgranular fracture, and the cause of the formation of the naphthalene fracture is that the coarse austenite grains form the intragranular texture, and the stability is very high. When the ferrite is converted to ferrite during the cooling process, the texture is still retained. The stone shaped fracture has obvious coarse grain, the surface has no metallic luster, the color is dark and the intergranular fracture. The cause of the stone shaped fracture is the increase of the solubility of the nonmetallic inclusion under the superheated temperature. In the cooling process, the nonmetallic inclusions are precipitated from the oversaturated coarse austenite and encircled the ordral grain to form brittle crystalline shell. The mechanical properties of the overheated forged blank are extremely poor. The naphthalene like fracture can eliminate the intragranular texture through high temperature normalizing, and the stone shaped fracture is difficult to be corrected by heat treatment. After the die forging is formed, it can not be saved once the stone shaped fracture is found.
  1. 联系人:黄经理
  2. 电话:+639277308203
  3. 手机娱乐:+639277308203
  4. 网址:www.moduanjiann.com
  5. 地址:凤凰娱乐市南市区朱庄工业区

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