碳钢表面粉末包埋法渗铝的实验研究
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摘要
目的解决粉末包埋渗铝过程中渗剂粘结导致渗铝层表面质量差的问题,在无惰性气体保护气氛中,在Q235钢表面制备出耐高温氧化、耐高温硫化和耐腐蚀的渗铝层。方法采用粉末包埋渗铝法,通过改变渗剂中填充剂的成分,解决渗剂粘结导致表面质量变差的问题,研究渗铝温度、保温时间对渗层试样表面质量及渗铝层厚度的影响,确定最佳渗铝条件。使用电子显微镜观察渗铝层表面质量并测定渗铝层厚度,采用能谱仪分析渗铝层主要元素分布,采用X射线衍射仪分析渗铝层物相组成,采用显微硬度计检测渗铝层硬度变化。结果采用成分为15%铝粉+5%氯化铵+75%氧化铝+5%石墨粉的渗剂,在无惰性气体保护下900℃保温4h,获得渗铝层厚度约为370μm的渗铝试样。渗铝层由外向内依次为铝化物层、过渡层和基体,铝化物层主要含有Al、Fe两种元素,原子百分比保持在7:3左右,主要物相为Fe2Al5,硬度达到896HV0.1,远高于基体硬度。结论渗剂中添加适量的石墨粉能够改善渗铝层表面质量,增加渗层厚度,过多的石墨粉反而不利于表面质量改善和渗铝层厚度的增长。渗铝层厚度随渗铝温度的升高先增大后减小,与保温时间呈抛物线关系。
The work aims to overcome the short comings of poor surface quality of aluminized layer and powder boning during aluminizing process and prepare an aluminized layer resistant to high temperature oxidation,high temperature sulfurization and corrosion on the surface of Q235 steel in an atmosphere not protected by inert gas. Aluminizing by powder pack cementation was adopt to change the filler constituent of aluminizing medium to solve the problem of poor surface quality caused by bonding of aluminizing medium. The effect of aluminizing temperature and holding time on the surface quality and thickness of aluminized layer was studied to determine the best aluminizing condition. The surface quality and the thickness of the aluminized layer were observed by electron microscope. The distributions of main elements on aluminized layer were analyzed by energy spectrometer. The phase composition of aluminized layer was studied by XRD. The hardness change in the aluminized layer was detected by microhardness tester.An aluminized layer with a thickness of about 370μm was prepared by the powder composed of 15%aluminum powder,5%ammonium chloride,75%alumina and 5%graphite under 900℃for 4 hours in a non-protective atmosphere.The aluminized layer was aluminide layer,transition layer and matrix from outside to inside.The aluminide layer mainly contained two elements including Al and Fe and the atomic ratio remained at 7:3.The main phase wasand the hardness of aluminide layer reached 896HV0.1 which was much higher than that of the substrate.Adding some graphite in the powder can improve the surface quality of the aluminized layer and increase the thickness of the layer,while excessive graphite powder is not beneficial to the improvement of surface quality and the thickness growth of aluminized layer.The thickness of the aluminized layer increases first and then decreases with the increasing of the aluminizing temperature and has a parabolic relationship with the holding time.
The work aims to overcome the short comings of poor surface quality of aluminized layer and powder boning during aluminizing process and prepare an aluminized layer resistant to high temperature oxidation,high temperature sulfurization and corrosion on the surface of Q235 steel in an atmosphere not protected by inert gas. Aluminizing by powder pack cementation was adopt to change the filler constituent of aluminizing medium to solve the problem of poor surface quality caused by bonding of aluminizing medium. The effect of aluminizing temperature and holding time on the surface quality and thickness of aluminized layer was studied to determine the best aluminizing condition. The surface quality and the thickness of the aluminized layer were observed by electron microscope. The distributions of main elements on aluminized layer were analyzed by energy spectrometer. The phase composition of aluminized layer was studied by XRD. The hardness change in the aluminized layer was detected by microhardness tester.An aluminized layer with a thickness of about 370μm was prepared by the powder composed of 15%aluminum powder,5%ammonium chloride,75%alumina and 5%graphite under 900℃for 4 hours in a non-protective atmosphere.The aluminized layer was aluminide layer,transition layer and matrix from outside to inside.The aluminide layer mainly contained two elements including Al and Fe and the atomic ratio remained at 7:3.The main phase wasand the hardness of aluminide layer reached 896HV0.1 which was much higher than that of the substrate.Adding some graphite in the powder can improve the surface quality of the aluminized layer and increase the thickness of the layer,while excessive graphite powder is not beneficial to the improvement of surface quality and the thickness growth of aluminized layer.The thickness of the aluminized layer increases first and then decreases with the increasing of the aluminizing temperature and has a parabolic relationship with the holding time.
引文
[1]HMSOLIM A N,KEMOHAM E D,EL-AZIM M,et al.Oxidation resistance of the aluminide coating formed on carbon steels[J].Journal of materials science&technology,1997,13(5):383-388.
[2]HOUNGIOU C,CHEVALIER S,LARPIN J P.High temperature oxidation behavior of iron aluminide diffusion coatings[J].Oxidation of metals,2006,65(5):409-439.
[3]TORTORELLI P F,NATESAN K.Critical factors affecting the high-temperature corrosion performance of iron aluminides[J].Materials science&engineering A,1998,258(1-2):115-125.
[4]HU G,XU Z,LIU J,et al.Microstructure and corrosion resistance of simultaneous Al-Fe coating on copper by pack cementation[J].Surface&coatings technology,2009,203(22):3392-3397.
[5]PEI Y,ZHOU C.Improved hot corrosion resistance of Dy-Co-modified aluminide coating by pack cementation process on nickel base superalloys[J].Corrosion science,2016,112:710-717.
[6]黄敦伟,胡爱萍,张宏伟,等.热浸渗铝X70管线钢扩渗工艺研究[J].表面技术,2013,42(4):72-75.HUANG Dun-wei,HU Ai-ping,ZHANG Hong-wei,et al.Research on hot diffusion aluminizing process of X70pipe line steel[J].Surface technology,2013,42(4):72-75.
[7]頡向旭,王宇.碳钢渗铝工艺研究进展[J].热处理技术与装备,2010,31(5):1-5.XIE Xiang-xu,WANG Yu.Reasearch progress on aluminizing process of carbon steel[J].Heat treament technology and equipment,2010,31(5):1-5.
[8]张冀翔,徐修炎,宋健斐,等.钢的渗铝工艺技术及性能研究进展[J].表面技术,2018,47(2):218-224.ZHANG Ji-xiang,XU Xiu-yan,SONG Jian-fei,et al.Research progress of steel aluminizing technology and performance[J].Surface technology,2018,47(2):218-224.
[9]XIANG X,WANG X,ZHANG G,et al.Preparation technique and alloying effect of aluminide coatings as tritium permeation barriers:A review[J].International journal of hydrogen energy,2015,40(9):3697-3707.
[10]GEIB F D,RAPP R A.Simultaneous chromizing:Aluminizing coating of low-alloy steels by a halideactivated pack-cementation process[J].Oxidation of metals,1993,40(3-4):213-228.
[11]WANG Y Q,ZHANG Y,WILSON D A.Formation of aluminide coatings on ferritic-martensitic steels by a low-temperature pack cementation process[J].Surface&coatings technology,2010,204(16-17):2737-2744.
[12]PEREZ F J,HIERRO M P,TRILLEROS J A,et al.Iron aluminide coatings on ferritic steels by CVD-FBR technology[J].Intermetallics,2006,14(7):811-817.
[13]XIANG Z D,DATTA P K.Pack aluminisation of low alloy steels at temperatures below 700℃[J].Surface&coatings technology,2004,184(1):108-115.
[14]王修春,李木森,董瑞华,等.机械能助渗铝组织与性能研究[J].材料热处理学报,2007,28(6):118-122.WANG Xiu-chun,LI Mu-sen,DONG Rui-hua,et al.Study on mechanical energy aided aluminizing an coldrolled 08F steel sheet[J].Transactions of materials and heat treatment,2007,28(6):118-122.
[15]赵延灵,李国成,李文戈.碳钢粉末渗铝试验研究[J].中国石油大学学报:自然科学版,2003,27(1):57-59.ZHAO Yan-ling,LI Guo-cheng,LI Wen-ge.Experimental study on powder aluminizing cementation of carbon steel[J].Journal of the university of petroleum china(edition of natural science),2003,27(1):57-59
[16]张超,宋义全.碳钢渗铝的组织与腐蚀行为研究[J].热加工工艺,2015(2):178-181.ZHANG Chao,SONG Yi-quan.Experimental study on microstructure and corrosion behavior of carbon steel after aluminizing[J].Hot working technology,2015(2):178-181.
[17]盛长松,晁君瑞,苏文志.渗铝、共渗技术及钢材防腐蚀[M].北京:中国石化出版社,2015.SHENG Chang-song,CHAO Jun-rui,SU Wen-zhi.Aluminizing and copenetration technology and steel corrosion protection[M].Beijing:Sinopec Press,2015.
[18]戚正风.固态金属中的扩散与相变[M].北京:机械工业出版社,1998.QI Zheng-feng.Diffusion and phase transition in solid metal[M].Beijing:Machinery Industry Press,1998.
[19]徐恒钧.材料科学基础[M].北京:北京工业大学出版社,2001.XU Heng-jun.Material science foundation[M].Beijing:Beijing University of Technology Press,2001
[20]ZHU Xiao-lin,YAO Zheng-jun,GU Xue-dong,et al.Microstructure and corrosion resistance of Fe-Al intermetallic coating on 45 steel synthesized by double glow plasma surface alloying technology[J].Transactions of nonferrous metals society of China,2009,19(1):143-148.
[21]唐仁政,田荣璋.二元合金相图及中间相晶体结构[M].长沙:中南大学出版社,2009.TANG Ren-zheng,TIAN Rong-zhang.Binary alloy phase diagrams and crystal structure of intermediate phase[M].Changsha:Central South University Press,2009.
[2]HOUNGIOU C,CHEVALIER S,LARPIN J P.High temperature oxidation behavior of iron aluminide diffusion coatings[J].Oxidation of metals,2006,65(5):409-439.
[3]TORTORELLI P F,NATESAN K.Critical factors affecting the high-temperature corrosion performance of iron aluminides[J].Materials science&engineering A,1998,258(1-2):115-125.
[4]HU G,XU Z,LIU J,et al.Microstructure and corrosion resistance of simultaneous Al-Fe coating on copper by pack cementation[J].Surface&coatings technology,2009,203(22):3392-3397.
[5]PEI Y,ZHOU C.Improved hot corrosion resistance of Dy-Co-modified aluminide coating by pack cementation process on nickel base superalloys[J].Corrosion science,2016,112:710-717.
[6]黄敦伟,胡爱萍,张宏伟,等.热浸渗铝X70管线钢扩渗工艺研究[J].表面技术,2013,42(4):72-75.HUANG Dun-wei,HU Ai-ping,ZHANG Hong-wei,et al.Research on hot diffusion aluminizing process of X70pipe line steel[J].Surface technology,2013,42(4):72-75.
[7]頡向旭,王宇.碳钢渗铝工艺研究进展[J].热处理技术与装备,2010,31(5):1-5.XIE Xiang-xu,WANG Yu.Reasearch progress on aluminizing process of carbon steel[J].Heat treament technology and equipment,2010,31(5):1-5.
[8]张冀翔,徐修炎,宋健斐,等.钢的渗铝工艺技术及性能研究进展[J].表面技术,2018,47(2):218-224.ZHANG Ji-xiang,XU Xiu-yan,SONG Jian-fei,et al.Research progress of steel aluminizing technology and performance[J].Surface technology,2018,47(2):218-224.
[9]XIANG X,WANG X,ZHANG G,et al.Preparation technique and alloying effect of aluminide coatings as tritium permeation barriers:A review[J].International journal of hydrogen energy,2015,40(9):3697-3707.
[10]GEIB F D,RAPP R A.Simultaneous chromizing:Aluminizing coating of low-alloy steels by a halideactivated pack-cementation process[J].Oxidation of metals,1993,40(3-4):213-228.
[11]WANG Y Q,ZHANG Y,WILSON D A.Formation of aluminide coatings on ferritic-martensitic steels by a low-temperature pack cementation process[J].Surface&coatings technology,2010,204(16-17):2737-2744.
[12]PEREZ F J,HIERRO M P,TRILLEROS J A,et al.Iron aluminide coatings on ferritic steels by CVD-FBR technology[J].Intermetallics,2006,14(7):811-817.
[13]XIANG Z D,DATTA P K.Pack aluminisation of low alloy steels at temperatures below 700℃[J].Surface&coatings technology,2004,184(1):108-115.
[14]王修春,李木森,董瑞华,等.机械能助渗铝组织与性能研究[J].材料热处理学报,2007,28(6):118-122.WANG Xiu-chun,LI Mu-sen,DONG Rui-hua,et al.Study on mechanical energy aided aluminizing an coldrolled 08F steel sheet[J].Transactions of materials and heat treatment,2007,28(6):118-122.
[15]赵延灵,李国成,李文戈.碳钢粉末渗铝试验研究[J].中国石油大学学报:自然科学版,2003,27(1):57-59.ZHAO Yan-ling,LI Guo-cheng,LI Wen-ge.Experimental study on powder aluminizing cementation of carbon steel[J].Journal of the university of petroleum china(edition of natural science),2003,27(1):57-59
[16]张超,宋义全.碳钢渗铝的组织与腐蚀行为研究[J].热加工工艺,2015(2):178-181.ZHANG Chao,SONG Yi-quan.Experimental study on microstructure and corrosion behavior of carbon steel after aluminizing[J].Hot working technology,2015(2):178-181.
[17]盛长松,晁君瑞,苏文志.渗铝、共渗技术及钢材防腐蚀[M].北京:中国石化出版社,2015.SHENG Chang-song,CHAO Jun-rui,SU Wen-zhi.Aluminizing and copenetration technology and steel corrosion protection[M].Beijing:Sinopec Press,2015.
[18]戚正风.固态金属中的扩散与相变[M].北京:机械工业出版社,1998.QI Zheng-feng.Diffusion and phase transition in solid metal[M].Beijing:Machinery Industry Press,1998.
[19]徐恒钧.材料科学基础[M].北京:北京工业大学出版社,2001.XU Heng-jun.Material science foundation[M].Beijing:Beijing University of Technology Press,2001
[20]ZHU Xiao-lin,YAO Zheng-jun,GU Xue-dong,et al.Microstructure and corrosion resistance of Fe-Al intermetallic coating on 45 steel synthesized by double glow plasma surface alloying technology[J].Transactions of nonferrous metals society of China,2009,19(1):143-148.
[21]唐仁政,田荣璋.二元合金相图及中间相晶体结构[M].长沙:中南大学出版社,2009.TANG Ren-zheng,TIAN Rong-zhang.Binary alloy phase diagrams and crystal structure of intermediate phase[M].Changsha:Central South University Press,2009.