【正文】 定。從表中可以看到，偏析系數(shù)的最大與最小值之間的正常寬展為23%25%。與此相反，未攪拌的一些流次中，%49%. 由分析可以看出，偏析平均值差異并不顯著。但是，表達(dá)為標(biāo)稱偏差的偏析寬展帶在經(jīng)攪拌的小方坯中減小了大約一半。就第一爐來研究中間包過熱度和拉速對高碳鋼(1074)偏析的影響。該爐不同流次的澆鑄變量被仔細(xì)地加以區(qū)分)。開澆時(shí)的中間包過熱度為5290，在接近澆鑄結(jié)束時(shí)降至3239。C. 雖然在這些澆鑄條件下，各流的偏析沒有明顯區(qū)別，應(yīng)該指出的是以低過熱度澆鑄的流次的偏析寬展較小。這些流次的偏析系數(shù)偏差比以較高過熱度澆鑄的流次大約小10%。偏析系數(shù)分布直方圖表明同以52℃的過熱度澆鑄的三個(gè)流次的偏析最大值K≤，以32℃的過熱度澆鑄的2/3流次的偏析系數(shù)最大值較低，即K≤ 。 試驗(yàn)結(jié)果表明:高過熱度情況下，拉速變化在20%范圍內(nèi)，對經(jīng)攪拌的小方坯的碳偏析沒有明顯的作用。不采用結(jié)晶器電磁攪拌進(jìn)行澆鑄，拉速繼續(xù)銳減，如表4(第4流)和表5(第3爐)所列情況，不會(huì)產(chǎn)生采用攪拌所取得的效果。 工業(yè)實(shí)踐和實(shí)驗(yàn)結(jié)果都表明:結(jié)晶器內(nèi)充分?jǐn)嚢?，使以較高中間包過熱度和拉速澆鑄高碳鋼和合金鋼成為可能，從而改善碳偏析。K阿亞他及其同事還發(fā)現(xiàn)，采用結(jié)晶器電磁攪拌澆鑄高碳鋼，過熱度在50℃范圍內(nèi)對偏析沒有明顯的不良影響。但繼續(xù)提高過熱度會(huì)導(dǎo)致偏析上升。6結(jié)論根據(jù)本文得出的結(jié)果可做如下結(jié)論:，可以控制結(jié)晶器內(nèi)的攪拌運(yùn)動(dòng)，這對敞開澆鑄和浸人式澆鑄十分必要。，改善了高碳鋼和合金鋼小方坯的質(zhì)量。最顯著的改進(jìn)是在凝固組織和中心碳偏析方面。由柱狀晶向樹枝晶和等軸晶的結(jié)構(gòu)轉(zhuǎn)變使采用了攪拌的小方坯的碳偏析分布形狀和數(shù)量發(fā)生了變化。主要由于減小了偏析峰值的出現(xiàn)及數(shù)量，偏析的最大和最小值之間的差幅明顯減小。，可以使高碳鋼和合金鋼的拉速分別提高31%和25%0以高達(dá)52℃的過熱度及如此高的拉速進(jìn)行澆鑄，未對小方坯質(zhì)量產(chǎn)生不良影響。生產(chǎn)統(tǒng)計(jì)表明:大約95% mm線材的偏析程度根據(jù)6級(jí)評(píng)級(jí)表為2級(jí)或更好一些，消除了馬氏體的出現(xiàn)。因此，產(chǎn)品得到了用戶的充分認(rèn)可。Continuous Casting of HighCarbon and Alloy Steel Billets with inMold DualCoil Electromagnetic Stirring SystemSidbecDosco (Ispat )Inc. J Limoges Enterprises, a division of Inverpower Controls Ltd. L Beitelman1 introductionIn 1994, West German Baker the Si branch pany installed the new development crystallizer interior electromagnetism to stir the system together (crystallizer electromagnetism to stir), transformed a part as small squares semifinished product Lian Zhuji, its goal was the enhancement casting condition product quality and Lian Zhuji the productivity.This system is a system which is posed by two sets of induction coils, may cause the crystallizer liquid level area and other parts produces different intensity stirring. This operation flexibility is the existing singleinductor crystallizer electromagnetism mixer is unable to achieve. This pany hoped the new system can adapt two kind of casting operations, namely:Decides the diameter drainage opening casting and the use soaks the human type drainage opening to soak the human type casting.This article narrated has used the double coil crystallizer electromagnetism to stir, small squares semifinished product surface and internal quality (namely:The coagulation organization and the central carbon segregation) obtains the effect, as well as the highcarbon steel line material quality and Lian Zhuji the productivity obtains improvement. In the liquid level area stirs the intensity to soak the human type long drainage opening the corrosive nature also to discuss in this article.2 production equipment and technical process summaryThe special steel (SBQ) the good material and the highcarbon steel line material uses the molten steel in 180 t, 130 MVA electric stove (eccentric furnace bottom tapping) produces. Uses the direct return to original state iron ball group and the scrap steel reduces in the product as the raw material the remaining element. In front of casting, molten steel in hot metal ladle furnace refining. In six lingers the casting machine on pouring to cast 120,140 and 160 mm= small squares semifinished product. The silicon manganese deaeration steel uses opens wide the type casting, uses the Pollar nitrogen protection drainage opening to prevent two times of oxidations. The majority of aluminum calm steel uses skids the drainage opening and soaks the human type drainage opening to carry on soaks the human type casting. The special steel small squares semifinished product uses above two ways casting.3 pair of coils crystallizers electromagnetism stirs the systemThis system like chart 1 shows. Sees to, a set stirs the coil to place lower part the crystallizer, another set places in the liquid level area. Lower part stirs the coil to stir as the conventional crystallizer electromagnetism, carries out the host to stir the duty, but the liquid level area coil produces magnetism place influence steel water volume is very limited. Relative and the main coil says, the liquid level area coil plays the assistance role, is called as the exchange to stir the regulator (ACSM) . Chart 1 The double coil electromagnetism stirs the schematic drawingThe crystallizer electromagnetism stirs with ACSM by the different power source feed, may control the intensity, the frequency and the hand of rotation separately, produces the different magnetic field.If two magnetic fields hand of rotation is consistent, according to the casting request, the liquid level area stirs the intensity to be possible through to increase ACSM to lose the human electric current to strengthen, also may through reduce even shuts off the ACSM electric current to weaken. Establishes the ACSM magnetic field hand of rotation stirs the magnetic field direction with the crystallizer electromagnetism to be opposite, may cause to stir the intensity further to weaken. In this kind of situation, the reversion games which produces by ACSM affects the crystallizer electromagnetism to stir stirs the movement. Such two directions opposite stir the movement possibly to achieve the balance in the liquid level, will stir the intensity to fall to the zero. Because the liquid level area stirs the direction to be opposite, in the crystallizer other parts stir the intensity to be able to have the certain degree to weaken.West German Baker the Si branch pany installs together the double coil crystallizer electromagnetism stirs the system main parameter like table 1 to show.4 experimentsIn order to determine the crystallizer electromagnetism to stir to the product quality and Lian Zhuji the productivity accurate influence, in the production operation will accumulate the experience with the casting several stoves steel result will unify the analysis under the control condition. Table 2,3 listed separately experimented a stove steel the chemical position and the casting and stirs the parameter.Steel chemical position like table 2 arranges in order, coagulation scope very wide, therefore is