在鍛件加工加熱時會出現(xiàn)什么情況呢?

　　What happens when the die is heated?

　　1.氧化鈹：氧化鈹不只丟掉許多鋼材，而且降低鍛件加工的表面質(zhì)量和鍛模的使用壽命，若壓入金屬內(nèi)部，會構(gòu)成鍛件報廢。

　　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.脫碳：脫碳是指鋼表面的碳全部或有些被燒掉的現(xiàn)象。脫碳使表面出現(xiàn)軟點，降低表面的硬度、耐磨性還有疲勞強度。

　　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.過熱和過燒：過熱指鋼在加熱中逾越答應(yīng)的溫度今后，使晶粒長的粗大。過熱不利熱處理，使鋼變脆并且機械性能降低，但可通過鍛后正火或者退火來消除。過燒指由于加熱時刻太長，溫度太高，使金屬出現(xiàn)氧化物或有些熔化的現(xiàn)象。過燒無法彌補。

　　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.出現(xiàn)應(yīng)力：由于金屬內(nèi)、外受熱有差異，脹大不勻，發(fā)作內(nèi)應(yīng)力，稱熱應(yīng)力。加熱致使金相組織的先后改變也構(gòu)成應(yīng)力，稱組織應(yīng)力。這都會使工件在加熱中發(fā)作裂紋，致使車加工后工件發(fā)作裂紋而報廢。

　　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.橫斷面出現(xiàn)斷口：這種缺陷破壞了鋼的化學(xué)成分和組織均勻性，使淬火硬度降低，機械性能變壞。若退火時溫度過高而構(gòu)成石墨斷面，將不易切削加工且使淬火時過熱和變形。但退火時若欠熱或溫度偏低，則珠光體未能完全球化，也不利于切削和后來的熱處理。

　　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.