本文選題：離心鑄造　切入點：高碳鉻鐵　出處：《河南科技大學》2011年碩士論文　論文類型：學位論文

【摘要】：本文采用一臺爐子冶煉復(fù)合軋輥表面工作層和芯部所需鐵水,并通過外加高碳鉻鐵顆粒法和離心鑄造,將高碳鉻鐵顆粒直接加入旋轉(zhuǎn)的離心機模具中,制備軋輥輥身,再采用重力鑄造法澆注輥芯而制成了尺寸為Φ180mm×500mm的高鉻鑄鐵/球墨鑄鐵雙金屬復(fù)合軋輥鑄件。利用HR-150D型洛氏硬度計和JB-300B型擺錘式?jīng)_擊試驗機等力學性能檢測設(shè)備測試不同熱處理狀態(tài)下試樣的力學性能;借助MH-3數(shù)顯顯微硬度儀對高鉻鑄鐵與球墨鑄鐵結(jié)合界面附近的顯微硬度進行測量;采用光學顯微鏡、配備了EDAX能譜儀的JSM-5610LV型電子掃描電鏡和德國布魯克D8型X射線衍射儀等微觀分析儀器觀察和分析試樣的微觀組織;采用MMS-1G高速銷-盤摩擦磨損實驗機,對不同熱處理狀態(tài)下試樣的高速摩擦磨損特性進行研究,并借助電子掃描電鏡分析其磨損機理。 上述試驗結(jié)果表明: 1.采用外加顆粒法制備的高鉻鑄鐵-球墨鑄鐵雙金屬復(fù)合軋輥,熱處理工藝對其表面工作層的力學性能具有一定的影響。在900~1000℃奧氏體化溫度范圍內(nèi),隨著奧氏體化溫度的升高,宏觀硬度的變化趨勢為先增大后減小,而沖擊韌度略微下降,在950℃奧氏體化時,力學性能匹配良好。其力學性能可達到:沖擊韌性5.2~6.6J/cm~2;硬度HRC56.7~64.8。 2.復(fù)合軋輥表面高鉻鑄鐵層鑄態(tài)下的微觀組織為:合金碳化物+珠光體+殘余奧氏體。經(jīng)熱處理,其微觀組織變?yōu)?回火馬氏體+Cr_7C_3+殘余奧氏體+少量Cr_(23)C_6和Cr3C,初生碳化物的形貌呈條狀、塊狀和菊花狀等;在馬氏體基體上分布有大量顆粒狀回火碳化物,經(jīng)EDS分析,這些碳化物是含有Fe、C和Cr等元素的復(fù)合式碳化物。 3.所制備的雙金屬復(fù)合軋輥,其高鉻鑄鐵與球墨鑄鐵的連接界面清晰,兩種合金呈犬牙狀相互交織在一起,結(jié)合處無氣孔、夾雜、裂紋和空隙等鑄造缺陷;從球墨鑄鐵一側(cè)向高鉻鑄鐵層,球狀石墨的數(shù)量越來越少,尺寸越來越小;從高鉻鑄鐵一側(cè)向球鐵層,條、塊狀碳化物的數(shù)量越來越少,尺寸越來越小。在結(jié)合界面高鉻鑄鐵側(cè)的顯微硬度約為800HV,球墨鑄鐵側(cè)的顯微硬度約為350HV,可見,復(fù)合界面兩側(cè)顯微硬度的差別比較大,但是在結(jié)合界面處顯微硬度的降低比較緩和。表明,合金元素在結(jié)合界面處發(fā)生了擴散,兩種金屬達到良好的冶金結(jié)合。 4.高速摩擦磨損試驗表明,奧氏體化溫度、外加法向載荷和摩擦線速度均對復(fù)合軋輥耐磨層材料的高速摩擦磨損性能具有顯著影響。在試驗溫度范圍內(nèi),磨損失重量隨著奧氏體化溫度的升高發(fā)生變化,在950℃奧氏體化時磨損失重量最小,此時耐磨性最佳;在摩擦線速度不變時,隨著外加法向載荷的增加,復(fù)合軋輥耐磨層試樣的線磨損率逐步增大,而摩擦系數(shù)逐步減小;在外加法向載荷不變時,隨著摩擦線速度的增大,復(fù)合軋輥耐磨層試樣的線磨損率逐步增大,而摩擦系數(shù)逐漸減小。據(jù)分析,耐磨層材料的磨損機制主要為磨粒磨損、氧化磨損和粘著磨損。在相同的試驗條件下,所制備復(fù)合軋輥耐磨層材料銷試樣的磨損失重量、線磨損率和摩擦系數(shù)均小于高合金耐磨鋼的磨損失重量、線磨損率和摩擦系數(shù),表明所制備復(fù)合軋輥耐磨層材料的高速摩擦磨損性能優(yōu)于高合金耐磨鋼。
[Abstract]:This paper uses a furnace smelting composite roller surface layer and the core of the work required by the external hot metal, and high carbon ferrochrome particle method and centrifugal casting, high carbon ferrochrome particles directly into the centrifuge rotating mold, preparation roll, high chromium cast iron / by gravity casting casting roller core and made the size of 180mm in diameter and 500mm ductile cast iron bimetal composite casting roll. Pendulum impact testing machine and other mechanical properties of specimens under mechanical properties testing equipment to test different heat treatment using HR-150D Rockwell hardness tester and JB-300B type; with the help of MH-3 digital display micro hardness of high chromium cast iron and ductile iron binding the hardness near the interface were measured by optical microscope, JSM-5610LV; scanning electron microscope equipped with a EDAX spectrometer and the German Brook D8 type X ray diffraction analysis of microscopic observation and analysis of test instrument The microstructure and wear characteristics of samples under different heat treatment conditions were investigated by means of MMS-1G high-speed pin disc friction and wear test machine, and the wear mechanism was analyzed by electron scanning electron microscope.
The results of the above test show that:
1. used the high chromium cast iron particles prepared by the ductile cast iron bimetal composite roll, has certain effect of heat treatment on the surface of the working layer of the mechanical properties. At 900~1000 DEG C austenitizing temperature range, with the increase of austenitizing temperature, the change trend of macro hardness was increased first and then decreased, while the impact toughness decreased slightly at 950 DEG C during austenitizing, mechanical properties, good mechanical properties. It can be achieved: the impact toughness of 5.2~6.6J/cm~2 hardness of HRC56.7~64.8.;
2. composite roll surface of high chromium cast iron layer cast microstructure state for alloy carbide + pearlite + residual austenite. After heat treatment, the microstructure becomes: tempered martensite +Cr_7C_3+ residual austenite and a small amount of Cr_ (23) C_6 and Cr3C, the morphology of the primary carbide is strip, block shaped and chrysanthemum; in the martensite and granular tempered carbide, by EDS analysis, these carbides containing Fe, composite carbide C and Cr elements.
Double metal composite roll 3. preparation, the high chromium cast iron and ductile iron with clear interface, two kinds of alloys in the shape of a canine tooth intertwined, with no pores, inclusions, cracks and voids casting defects; ductile iron from one side to the high chromium cast iron layer number and spherical graphite the less, the size is getting smaller and smaller; from one side to the high chromium cast iron ductile iron layer, an increasing number of blocky carbides is less, the size is getting smaller and smaller. The micro hardness of high chromium cast iron side interface is about 800HV, the micro hardness of nodular cast iron side is about 350HV, can be seen, the composite interface on both sides of the hardness difference is relatively large, but in reducing the interface hardness of ease. Show that the alloy elements in the interface has spread, two kinds of metal to achieve good metallurgical combination.
4. high speed friction and wear test shows that the austenitizing temperature, applied normal load and friction velocity of composite roll wear layer materials of high-speed friction and wear properties have significant influence. In the experimental temperature range, the wear weight loss with the increase of austenitizing temperature change at 950 DEG C during austenitizing minimum weight losses at this time, the best wear resistance; the friction velocity is constant, with the increase of normal load, the wear resistant composite layer roll sample linear wear was gradually increased, while the friction coefficient gradually decreases; in addition to the load change, with the increase of friction velocity, the wear resistant composite layer sample rate of linear wear of roll gradually increased, and the friction coefficient decreases gradually. According to the analysis, the wear mechanism of the wear-resistant layer material is mainly abrasive wear, oxidation wear and adhesive wear. Under the same experimental conditions, the preparation of composite rolling The wear loss, wear rate and friction coefficient of the roll wear resistant material pin specimen are smaller than those of the high alloy wear resistant steel. The wear rate and friction coefficient indicate that the high speed friction and wear properties of the composite roll wear resistant material is better than that of the high alloy wear resistant steel.

【學位授予單位】：河南科技大學
【學位級別】：碩士
【學位授予年份】：2011
【分類號】：TB331

【參考文獻】

相關(guān)期刊論文 前10條

1 曹洪吉;宋延沛;王文焱;程麗;;載荷對顆粒增強鐵基復(fù)合材料摩擦性能的影響[J];表面技術(shù);2005年06期

2 馮明杰;王恩剛;王俊剛;赫冀成;;連續(xù)鑄造復(fù)合軋輥輥芯預(yù)熱的數(shù)值模擬[J];東北大學學報(自然科學版);2007年10期

3 符定梅;符寒光;;復(fù)合軋輥制造技術(shù)的研究進展[J];大型鑄鍛件;2006年02期

4 靳芳芳;王毛球;惠衛(wèi)軍;時捷;董瀚;李建錫;;奧氏體化溫度對25CrNi3 MoV鋼的組織和力學性能的影響[J];大型鑄鍛件;2007年01期

5 李秀青;宋延沛;;雙金屬復(fù)合軋輥鑄造工藝的研究現(xiàn)狀與展望[J];材料研究與應(yīng)用;2010年03期

6 惠衛(wèi)軍,董瀚,王毛球,陳思聯(lián),翁宇慶;淬火溫度對Cr-Mo-V系低合金高強度鋼力學性能的影響[J];金屬熱處理;2002年03期

7 朱達平;何洪亮;吳玉彬;畢洪偉;曹務(wù)勛;;離心鑄造噴射法復(fù)合軋輥材料的研究[J];機械工程師;2007年02期

8 熊運昌,梁秀山,楊凌平;熱軋輥的選材及熱處理[J];機械研究與應(yīng)用;2002年01期

9 王興衍;;高鉻三層復(fù)合結(jié)構(gòu)鑄鐵軋輥的試制研究[J];機械研究與應(yīng)用;2009年03期

10 楊雄;魏世忠;李繼文;張國賞;龍銳;;過共晶超高鉻鑄鐵合金的組織與性能[J];河南科技大學學報(自然科學版);2008年03期

相關(guān)博士學位論文 前1條

1 宋延沛;大斷面WC_p/Fe-C復(fù)合材料性能及梯度結(jié)構(gòu)形成機制研究[D];上海大學;2006年

相關(guān)碩士學位論文 前2條

1 張軍;雙金屬復(fù)合鑄造工藝的研究[D];鄭州大學;2006年

2 邵抗振;電磁半連續(xù)復(fù)合鑄造軋輥工藝研究[D];河南科技大學;2006年

，

本文編號：1650172