To compare the corrosion behavior of different stainless steels under typical condition of superheater in biomass fueled boiler, the experimental research was carried out. Commonly used boiler steels such as 20G, 12Cr1MoVG, Super304, SUS316, TP347H and HR3C were tested and the temperature arrangement of 550～700℃ was chosen. The corrosion characteristic curve is drawn through measuring the increment of sample weight. Detailed analysis using Energy Dispersive System(EDS), Scanning Electron Microscope(SEM) and X-ray Diffractometer(XRD) was also conducted to study the morphology features, element content and composition of corrosion products after the samples were collected. The result shows that under high-temperature, the order of those stainless steels’ resistance to KCl corrosion is HR3C>TP347H>Super304>SUS316>12Cr1MoVG>20G. The temperature and adhesion amount of KCl on the metal surface also have significant influence on the rate of corrosion. It was found that the nickel-chromium based passivation layer of the materials is reactive under KCl environment and the damage of this layer is the direct reason for high rate high-temperature corrosion.
［1］ JOHANSEN J M, JAKOBSEN J G, FRANDSEN F J. Release of K Cl and S during pyrolysis and combustion of high-chlorine biomass ［J］. Energy Fuels, 2011, 25(11): 4961-4971．
［2］ SANDBERG J, KARLSSON C, FDHILA R B .A 7 year long measurement period investigating the correlation of corrosion, deposit and fuel in a biomass fired circulated fluidized bed boiler ［J］. Applied Energy, 2011, 88(1): 99-110．
［3］ NIELSEN H P, FRANDSEN F J, DAM-JOHANSEN K. The implications of chlorine associated corrosion on the operation of biomass fired boilers ［J］.Progress in Energy and Combustion Science, 2000, 26(3):283-293．
［4］ LI Lian-ming, YU Chun-jiang, HUANG Fang, et al. Study on the deposits derived from a biomass circulating fluidized-bed boiler ［J］. Energy Fuels, 2012, 26(9): 6008-6014．
［5］ SKRIFVARS B, BACKMAN R, HUPA M, et al. Corrosion of superheater steel materials under alkali salt deposits part 1: the effect of salt deposit composition and temperature ［J］. Corrosion Science, 2008, 50(5):1274-1282．
［6］ SKRIFVARS B,WESTEN K M,HUPA M, et al. Corrosion of superheater steel materials under alkali salt deposits. part 2: SEM analyses of different steel materials ［J］ .Corrosion Science ,2010, 52(3):1011-1019．
［7］ 李庆, 宋军政, 聂志钢. 130t/h 燃生物质锅炉过热器管子腐蚀原因分析［J］. 发电设备, 2009, 3: 214-218．
Li Qing, Song Jun-zheng, Nie Zhi-gang. Cause analysis on corrosion of a 130t/h biomass-fired boilers superheater tubes ［J］. Power Equipment, 2009, 3: 214-218．
［8］ VAN LOO S, KOPPEJAN J. The handbook of biomass combustion and co-firing ［M］. ［S. l.］: Earthscan Ltd, 2008．
［9］ LITH S C V, FRANDSEN F J, MONTGOMERY M, et al. Lab-scale investigation of deposit-induced chlorine corrosion of superheater materials under simulated biomass-firing conditions. part 1: Exposure at 560° C［J］. Energy Fuels, 2009,23(7), 3457-3468．
［10］ DANIEL P L, RAPP R A, FONTANA M G, et al.Advances in corrosion science and technology［M］.New York:Plenum Press, 1976．
［11］ CHANG Y N, WEI F I. High-temperature chlorine corrosion of metals and alloys［J］.Journal of Materials Science,1991,26(14):3693-3698．
［12］ RAPP R A,DEVAN J H,DOUGLASS D L. High temperature corrosion in energy systems ［J］.Master Sci Eng, 1981,50(1):117．
［13］ FOLKESON N, JONSSON T, HALVARSSON M, et al.The influence of small amounts of KCl (s) on the high temperature corrosion of a Fe-225Cr-1Mo steel at 400and 500℃［J］ . Materials and Corrosion, 2011, 62(7):606-615．
［14］SHINATA Y .Accelerated oxidation rate of chromium induced by sodium chloride ［J］.Oxidation of Metals, 1987,27(5):315-332．
［15］ JONSSON T, FOLKESON N, SVENSSON J E, et al. An ESEM in situ investigation of initial stages of the KCl induced high temperature corrosion of a Fe–225 Cr–1Mo steel at 400° C ［J］. Corrosion Science ,2011, 53(6): 2233-2246．
［16］ LEHMUSTO J,SKRIFVARS B J,YRJAS P, et al.High temperature oxidation of metallic chromium exposed to eight different metal chlorides ［J］. Corrosion Science, 2011,53(10):3315-3323．
［17］ LEHMUSTO J, SKRIFVARS B J, YRJAS P, et al. Comparison of potassium chloride and potassium carbonate with respect to their tendency to cause high temperature corrosion of stainless 304L steel［J］.Fuel Processing Technology,2013,105: 98-105．
［18］ PETTERSSON J, FOLKESON N, JOHANSSON L G, et al. The effects of KCl, K2SO4 and K2CO3 on the high temperature corrosion of a 304-type austenitic stainless steel［J］.Oxidation of metals,2011,76(1/2):93-109．
［19］ 韦威,黄芳,余春江,et al.生物质燃烧设备高温腐蚀问题初探［J］.能源工程,2011, (2):23-28.
WEI Wei,HUANG Fang,YU Chun-jiang,et al. Primary investigation of high-temperature corrosion problems in biomass combustion equipment ［J］.Energy Engineering,2011, (2):2328.
［20］ 余春江,骆仲泱,张文楠.碱金属及相关无机元素在生物质热解转化析出［J］.燃烧化学学报,2000,28（5）:420-425．
YU Chun-jiang, LUO Zhong-yang, Zhang Wen-nan. Inorganic material emission during biomass pyrolysis ［J］.Journal Of Fuel Chemistry And Technology , 2000, 28(5):420-425．
［21］ 印佳敏,吴占松.TP347H在生物质锅炉过热器气相条件下的腐蚀性（II）［J］.热力发电,2009 ,38（7）：27-31．
YIN Min-jia, WU Zhan-song. Corrosion characters of TP347H steel under atmosphere of superheaters of biomass burned boilers(II)［J］. Thermal Power Generation, 2009 ,38(7):2731.
