了進(jìn)步大型、超大型自由鍛件鋼錠的勻稱性與純凈性,中國一重集成創(chuàng)新發(fā)明了一系列冶煉及鑄錠手藝。
⑴低硅控鋁鋼冶煉手藝。
為了削減同化物并獲取本質(zhì)細(xì)晶粒鋼,發(fā)明了低硅控鋁鋼生產(chǎn)手藝。既進(jìn)步了鋼液的純凈度、得到本質(zhì)細(xì)晶粒鋼,另有效地控制了超大型鋼錠的成分偏析,低落鋼錠中的同化物和善體含量。采用低硅控鋁鋼冶煉澆注技巧生產(chǎn)出了成分勻稱、同化物少的高品質(zhì)鍛件。
⑵保護(hù)澆注。
1)新型中間包。
為了削減鋼錠澆注歷程當(dāng)中鋼渣卷入鋼錠模內(nèi),模仿了冶金行業(yè)連鑄歷程當(dāng)中采用“擋墻”、“擋壩”的履歷,發(fā)明了帶有“擋墻”、“擋壩”的新型中間包。數(shù)值模擬和工程實(shí)際證明,相比于古代的圓形中間包,新型中間包澆注的超大型鋼錠中的同化物含量大幅度削減。
2)長水口保護(hù)澆注。
澆注歷程當(dāng)中注流卷吸空氣是鋼液二次氧化的緊張緣故。鋼液二次氧化不但會(huì)形成無益的氧化物同化導(dǎo)致鍛件報(bào)廢,并且還會(huì)使鋼錠中的氣體(H 、O 、N)含量增高。而氣體含量高又是導(dǎo)致超大型鍛件缺陷的要緊緣故之一。為了幸免鋼液的二次氧化,在模仿冶金行業(yè)履歷的底子上,開發(fā)了長水口保護(hù)澆注手藝,有效地幸免了鋼液的二次氧化。
3)二次補(bǔ)澆。
偏析是鋼液選分結(jié)晶和鋼錠凝集歷程的勢(shì)必后果,鋼錠越大,偏析及縮孔等缺陷越緊張。中國一重在用平衡C含量為0.62%的459t鋼錠研制支承輥時(shí),曾在靠近冒口端的輥身部位發(fā)生斷裂。經(jīng)對(duì)斷裂部位宏觀形貌說明,發(fā)現(xiàn)二次縮孔緊張,冒口下部的C含量竟高達(dá)1.16%,靠近尺度值的2倍。為打聽決這一困難,發(fā)明了鋼錠二次補(bǔ)澆手藝,使冒口下部的C含量降至0.8%擺布,勝利生產(chǎn)出5m、5.5m支承輥用超大型鋼錠。
鍛件廠家定制哪家好,就找唐山盛通鍛造有限公司。
In order to improve the symmetry and purity of large and super large free forging steel ingots, China has integrated a series of smelting and ingot casting techniques.
(1) Low silicon controlled aluminum steel smelting technology.
In order to reduce the assimilation and obtain the intrinsic fine grain steel, a low silicon controlled aluminum steel production technique was invented. It not only improves the purity of the molten steel, but also obtains the intrinsic fine-grain steel. It also effectively controls the segregation of the composition of the super-large steel ingot, and the assimilation and good body content in the ingot. The use of low-silicon controlled aluminum steel smelting and casting techniques has produced high-quality forgings with well-balanced components and few assimilates.
(2) Protection pouring.
1) New tundish.
In order to reduce the steel slag involved in the ingot casting process, imitating the history of the “retaining wall” and “blocking dam” in the continuous casting process of the metallurgical industry, the invention of the new middle with “retaining wall” and “blocking dam” package. Numerical simulations and engineering have proved that the assimilates in the ultra-large steel ingots cast by the new tundish are greatly reduced compared to the ancient round tundish.
2) Long nozzle protection pouring.
The injection of air in the pouring process is the tension of the secondary oxidation of molten steel. The secondary oxidation of molten steel not only causes undesired oxide assimilation, but also causes the forgings to be scrapped, and also increases the content of gases (H, O, N) in the ingots. The high gas content is one of the reasons for the defects of ultra-large forgings. In order to survive the secondary oxidation of molten steel, in the imitation of the metallurgical industry resume, the development of the long nozzle protection casting technology, effectively spared the secondary oxidation of molten steel.
3) Secondary filling.
Segregation is the inevitable consequence of the selection of crystallization of steel and the agglomeration of steel ingots. The larger the steel ingot, the more tight the defects such as segregation and shrinkage. When China developed a support roll with a 459t steel ingot with a balanced C content of 0.62%, it broke at the roll body near the riser end. After explaining the macroscopic morphology of the fracture site, it was found that the second shrinkage cavity was tight, and the C content in the lower part of the riser was as high as 1.16%, which was close to twice the scale value. In order to inquire about this difficulty, the steel ingot secondary refilling technique was invented, and the C content in the lower part of the riser was reduced to 0.8%, and the ultra-large steel ingot for the 5m and 5.5m support rolls was successfully produced.
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