鑄鐵軋輥表面激光強(qiáng)化性能研究
發(fā)布時間：2018-07-17 05:01
【摘要】：激光表面強(qiáng)化技術(shù)近幾年在工業(yè)領(lǐng)域的失效零件修復(fù)方面應(yīng)用很廣泛。激光作為清潔能源以其能量密度大、加工效率高，修復(fù)質(zhì)量好等優(yōu)點(diǎn)越來越受到青睞。通過激光對失效零件表面進(jìn)行修復(fù)或者強(qiáng)化，可以大大延長零件的使用壽命，為企業(yè)節(jié)省成本，節(jié)約資源。 本研究采用光纖激光和CO2激光對軋輥表面進(jìn)行合金化處理，對兩種激光的合金化層性能進(jìn)行對比分析。合金化層的合金材料為WC-6Co，其中Co元素主要起粘結(jié)WC硬質(zhì)相的作用。因為所選用的WC為納米級的細(xì)化陶瓷材料，在高能量密度的激光照射下，部分WC硬質(zhì)相顆粒產(chǎn)生分解，，與基體材料形成復(fù)雜碳化物。未分解的WC硬質(zhì)相在熔池充分混合而彌散分布在合金化層，提高了合金化層的硬度和耐磨性。首先通過大量實驗，確定了軋輥激光合金化的最佳工藝參數(shù)。在最佳工藝參數(shù)條件下，采用光學(xué)顯微鏡、掃描電鏡和X射線衍射儀等分析方法，對最佳工藝參數(shù)條件下獲得的激光合金化層和熱影響區(qū)的組織及相組成進(jìn)行了研究分析；通過耐磨性實驗，分析了合金化層的耐磨性能；利用顯微硬度計對合金化層及過渡區(qū)的顯微硬度和硬度分布進(jìn)行了檢測；通過冷熱疲勞實驗分析了合金化層的冷熱疲勞性能。 實驗結(jié)果表明，光纖激光合金化層常溫及高溫的耐磨性能均比母材提高了3倍，CO2激光合金化層提高了2倍左右。激光合金化層硬度可達(dá)HV900，與母材相比提高了2~3倍。光纖激光合金化層深0.4mm，熱影響區(qū)深度為0.6mm，總強(qiáng)化深度約為1mm。與光纖激光同樣條件下，CO2激光合金化的總強(qiáng)化深度約為0.7mm。冷熱疲勞實驗顯示，兩種激光合金化層的裂紋敏感性略高于母材。兩種激光合金化層的組織基本相同，由亞共晶組織組成，其中共晶組織由馬氏體+復(fù)雜碳化物組成。熱影響區(qū)組織由針狀貝氏體和殘余奧氏體、板條狀馬氏體、原始存在石墨球及原始存在Fe3C構(gòu)成。
[Abstract]:Laser surface strengthening technology has been widely used in the field of industry in recent years. As a clean energy, laser is more and more popular because of its high energy density, high processing efficiency and good repair quality. Using laser to repair or strengthen the surface of invalid parts can greatly prolong the service life of the parts and save the cost and resources for the enterprises. In this study, optical fiber laser and CO2 laser were used to alloying the roller surface, and the properties of the alloying layer of the two kinds of laser were compared and analyzed. The alloy material of alloying layer is WC-6Co, in which Co plays the role of bonding WC hard phase. Because the WC is a fine ceramic material of nanometer size, some of the WC hard phase particles are decomposed under the laser irradiation of high energy density, forming complex carbides with the matrix material. The undecomposed WC hard phase is fully mixed in the molten pool and dispersed in the alloying layer, which improves the hardness and wear resistance of the alloying layer. Firstly, the optimum technological parameters of laser alloying of roller are determined by a large number of experiments. The microstructure and phase composition of the laser alloying layer and the heat-affected zone obtained under the optimum technological parameters were studied by means of optical microscope, scanning electron microscope and X-ray diffractometer. The wear resistance of alloyed layer was analyzed by wear resistance test, the microhardness and hardness distribution of alloying layer and transition zone were tested by microhardness meter, and the cold and thermal fatigue property of alloyed layer was analyzed by cold and hot fatigue experiment. The experimental results show that the wear resistance of the optical fiber laser alloying layer at room temperature and high temperature is 3 times higher than that of the base metal and the CO2 laser alloying layer is about 2 times higher than that of the base metal. The hardness of laser alloying layer can reach HV900, which is 3 times higher than that of base metal. The depth of fiber laser alloying layer is 0.4mm, the depth of heat-affected zone is 0.6mm, and the total strengthening depth is about 1mm. The total strengthening depth of CO _ 2 laser alloying is about 0.7 mm under the same condition as fiber laser. The cold and thermal fatigue tests show that the crack sensitivity of the two laser alloying layers is slightly higher than that of the base metal. The microstructure of the two laser alloying layers is basically the same and consists of hypoeutectic structure, in which the eutectic structure is composed of martensite complex carbides. The microstructure of the heat affected zone is composed of acicular bainite and retained austenite, lath martensite, original graphite sphere and original Fe3C.
【學(xué)位授予單位】：沈陽工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TG665
本文編號：2129129
[Abstract]:Laser surface strengthening technology has been widely used in the field of industry in recent years. As a clean energy, laser is more and more popular because of its high energy density, high processing efficiency and good repair quality. Using laser to repair or strengthen the surface of invalid parts can greatly prolong the service life of the parts and save the cost and resources for the enterprises. In this study, optical fiber laser and CO2 laser were used to alloying the roller surface, and the properties of the alloying layer of the two kinds of laser were compared and analyzed. The alloy material of alloying layer is WC-6Co, in which Co plays the role of bonding WC hard phase. Because the WC is a fine ceramic material of nanometer size, some of the WC hard phase particles are decomposed under the laser irradiation of high energy density, forming complex carbides with the matrix material. The undecomposed WC hard phase is fully mixed in the molten pool and dispersed in the alloying layer, which improves the hardness and wear resistance of the alloying layer. Firstly, the optimum technological parameters of laser alloying of roller are determined by a large number of experiments. The microstructure and phase composition of the laser alloying layer and the heat-affected zone obtained under the optimum technological parameters were studied by means of optical microscope, scanning electron microscope and X-ray diffractometer. The wear resistance of alloyed layer was analyzed by wear resistance test, the microhardness and hardness distribution of alloying layer and transition zone were tested by microhardness meter, and the cold and thermal fatigue property of alloyed layer was analyzed by cold and hot fatigue experiment. The experimental results show that the wear resistance of the optical fiber laser alloying layer at room temperature and high temperature is 3 times higher than that of the base metal and the CO2 laser alloying layer is about 2 times higher than that of the base metal. The hardness of laser alloying layer can reach HV900, which is 3 times higher than that of base metal. The depth of fiber laser alloying layer is 0.4mm, the depth of heat-affected zone is 0.6mm, and the total strengthening depth is about 1mm. The total strengthening depth of CO _ 2 laser alloying is about 0.7 mm under the same condition as fiber laser. The cold and thermal fatigue tests show that the crack sensitivity of the two laser alloying layers is slightly higher than that of the base metal. The microstructure of the two laser alloying layers is basically the same and consists of hypoeutectic structure, in which the eutectic structure is composed of martensite complex carbides. The microstructure of the heat affected zone is composed of acicular bainite and retained austenite, lath martensite, original graphite sphere and original Fe3C.
【學(xué)位授予單位】：沈陽工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TG665
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 沈風(fēng)剛;劉景鳳;;冶金軋輥堆焊技術(shù)綜述[J];中國表面工程;2006年03期
2 肖紅軍,彭云,馬成勇,田志凌;激光表面改性[J];表面技術(shù);2005年05期
3 葉宏;鑄鐵激光表面合金化的裂紋[J];重慶工業(yè)管理學(xué)院學(xué)報;1996年01期
4 李智,馬椿喻,劉相華,王國棟;激光表面合金化工藝進(jìn)展[J];材料科學(xué)與工程;1999年02期
5 郭麗環(huán);材料表面的激光合金化[J];大連大學(xué)學(xué)報;2003年02期
6 孔祥偉,史靜,徐建忠,王國棟;熱帶鋼軋機(jī)軋輥磨損預(yù)測[J];東北大學(xué)學(xué)報;2002年08期
7 李明喜,何宜柱,孫國雄;Ni基高溫合金表面激光熔覆Co基合金的組織[J];焊接學(xué)報;2002年06期
8 王維潔;國外激光鉻合金化的研究[J];激光技術(shù);1988年04期
9 梁二軍;梁會琴;晁明舉;趙棟;;三種形態(tài)WC對Ni60激光熔覆層的不同影響[J];激光雜志;2006年02期
10 肖運(yùn)鴻;德國激光技術(shù)現(xiàn)狀與加速發(fā)展我國激光制造技術(shù)和產(chǎn)業(yè)的建議[J];機(jī)器人技術(shù)與應(yīng)用;2003年05期
本文編號：2129129
本文鏈接：http://sikaile.net/kejilunwen/jinshugongy/2129129.html
最近更新
教材專著
