在锻件加工加热时会出现什么情况呢?

　　What happens when the die is heated?

　　1.氧化铍：氧化铍不只丢掉许多钢材，而且降低锻件加工的表面质量和锻模的使用寿命，若压入金属内部，会构成锻件报废。

　　1.: not only get rid of many steel beryllium beryllium oxide, and reduce the surface quality and the service life of forging die forging processing, if pressed into the metal inside, will constitute a forging scrap.

　　2.脱碳：脱碳是指钢表面的碳全部或有些被烧掉的现象。脱碳使表面出现软点，降低表面的硬度、耐磨性还有疲劳强度。

　　2. decarburization: decarburization is the phenomenon that all or some of the carbon on the surface of the steel is burned. Decarburization results in soft spots on the surface, lower surface hardness, wear resistance, and fatigue strength.

　　3.过热和过烧：过热指钢在加热中逾越答应的温度今后，使晶粒长的粗大。过热不利热处理，使钢变脆并且机械性能降低，但可通过锻后正火或者退火来消除。过烧指由于加热时刻太长，温度太高，使金属出现氧化物或有些熔化的现象。过烧无法弥补。

　　3. overheating and over burning: overheating refers to the steel in the heating exceed the promised temperature in the future, so that the long grain size. Overheating is detrimental to heat treatment, which makes the steel brittle and reduces mechanical properties, but can be eliminated by forging, normalizing, or annealing. The phenomenon of metal oxides or melting when the heating time is too long and the temperature is too high. Burns cannot make up.

　　4.出现应力：由于金属内、外受热有差异，胀大不匀，发作内应力，称热应力。加热致使金相组织的先后改变也构成应力，称组织应力。这都会使工件在加热中发作裂纹，致使车加工后工件发作裂纹而报废。

　　4. appear stress: because of metal inside and outside heating difference, swell uneven, internal stress, called thermal stress. Heating leads to the change of the metallographic structure, and it also forms the stress, which is called the organizational stress. This will cause the workpiece to crack during heating and cause the workpiece to crack and die.

　　5.横断面出现断口：这种缺陷破坏了钢的化学成分和组织均匀性，使淬火硬度降低，机械性能变坏。若退火时温度过高而构成石墨断面，将不易切削加工且使淬火时过热和变形。但退火时若欠热或温度偏低，则珠光体未能完全球化，也不利于切削和后来的热处理。

　　5. cross section fracture: this defect destroys the chemical composition and microstructure uniformity of the steel, makes quenching hardness decrease, mechanical performance deterioration. If the temperature is too high to form the graphite cross section, it will be difficult to cut and make it overheated and deformed during quenching. But when annealing is too hot or the temperature is low, pearlite is not fully spheroidization, and it is also unfavorable to cutting and subsequent heat treatment.