Abstract：Tensile behaviors at 20-600℃ and fatigue properties at room temperature of the SA508 Gr.3 Cl.1 steel were tested and analyzed. The results show that the SA508 Gr.3 Cl.1 is composed of upper bainite and carbide, the grain size is 8.0. Coarse D type ball oxide with moy level 1.0 which is distributed in the steel matrix is about 0.0325% (volume fraction) of the steel matrix. There are a large number of parallel and entangled dislocations distributing in the steel matrix, in addition to a large number of carbide particles, the precipitates are mainly Al6(Fe,Mn) particles with base-centered orthorhombic lattice. The yield strength and tensile strength decrease with the increase of temperature. The elongation remains at 20.2%-29.1%. The percentage reduction of area is relatively stable at 20-300℃, is about 70%; while it increases after 300℃, and the corresponding value reaches 90.2% at 600℃. Stretching results in the increase of microhardness of the steel matrix, but its value decreases with the increase of temperature, and the microhardness value is 225HV at 600℃. XRD analysis shows that stretching leads to no obvious phase transformation. The tensile properties meet the performance requirements of reactor internals in the large advanced PWR such as AP100 etc. The fatigue tests show that the fatigue limit of S-N curve of the steel is 268.64MPa. The average value of the JΙC is 331.2kJ/m2, and KIC is 269.07MPa·m1/2.
 张文广,李茂林,郭德朋,等.核电SA508-3钢研究进展[J].热加工工艺,2014,43(16):10-13.ZHANG W G,LI M L,GUO D P,et al.Study on progress of SA508-3 steel for nuclear power[J].Hot Working Technology,2014,43(16):10-13.
 刘文斌,李书瑞.我国核电承压设备用钢的发展现状与研究方向[J].钢铁研究,2011,39(5):58-62.LIU W B,LI S R.Recent development and research direction on the plate for nuclear pressure equipment in China[J].Research on Iron&Steel,2011,39(5):58-62.
 李昌义,刘正东,林肇杰.核电站反应堆压力容器用钢的研究与应用[J].特殊钢,2010,31(4):14-17.LI C Y,LIU Z D,LIN Z J.Research and application of steels for reactor pressure of nuclear power station[J].Special Steel,2010,31(4):14-17.
 GUO W,DONG S Y,FRANCIS J A,et al.Microstructure and mechanical characteristics of a laser welded joint in SA508 nuclear pressure vessel steel[J].Materials Science and Engineering:A,2015,625:65-80.
 BYUN T S,HONG J H,HAGGAG F M,et al.Measurement of through-the-thickness variations of mechanical properties in SA508 Gr.3 pressure vessel steels using ball indentation test technique[J].International Journal of Pressure Vessels and Piping,1997,74(3):231-238.
 迟露鑫,麻永林,邢淑清,等.核压力容器SA508-3钢高温性能试验分析[J].四川大学学报(工程科学版),2011,43(2):202-206.CHI L X,MA Y L,XING S Q,et al.Analysis on high temperature performance of SA508-3 steel for nuclear power[J].Journal of Sichuan University (Engineering Science Edition),2011,43(2):202-206.
 LIU J H,WANG L,LIU Y,et al.Effects of hydrogen on fracture toughness and fracture behaviour of SA508-Ⅲ steel[J].Materials Research Innovations,2014,18(Suppl 4):255-259.
 KIM I S,KANG S S.Dynamic strain aging in SA508-class 3 pressure vessel steel[J].International Journal of Pressure Vessels and Piping,1995,62(2):123-129.
 LEE S,KIM S,HWANG B,et al.Effect of carbide distribution on the fracture toughness in the transition temperature region of an SA 508 steel[J].Acta Materialia,2002,50(19):4755-4762.
 WU X Q,KIM I S.Effects of strain rate and temperature on tensile behavior of hydrogen-charged SA508 Cl.3 pressure vessel steel[J].Materials Science and Engineering:A,2003,348(1/2):309-318.
 KIM M C,PARK S G,LEE K H,et al.Comparison of fracture properties in SA508 Gr.3 and Gr.4N high strength low alloy steels for advanced pressure vessel materials[J].International Journal of Pressure Vessels and Piping,2015,131:60-66.
 KEMPF R,TROIANI H,FORTIS A M.Effect of lead factors on the embrittlement of RPV SA-508 cl 3 steel[J].Journal of Nuclear Materials,2013,434(1/3):411-416.
 李巨峰,李瑞峰,张玮,等.核岛主设备用SA508-Ⅲ钢锻件性能研究[J].热加工工艺,2016,45(7):185-187.LI J F,LI R F,ZHANG W,et al.Study on properties of SA508-Ⅲ steel forgings for nuclear island main equipments[J].Hot Working Technology,2016,45(7):185-187.
 赵勇桃,董俊慧,张韶慧,等.P92钢高温拉伸断口形貌的研究[J].材料工程,2015,43(4):85-91.ZHAO Y T,DONG J H,ZHANG S H,et al.High-temperature tensile fracture morphology of P92 steel[J].Journal of Materials Engineering,2015,43(4):85-91.
 胡庚祥,蔡珣,戎咏华.材料科学基础[M].上海:上海交通大学出版社,2000:172-210.HU G X,CAI X,RONG Y H.Fundamentals of material science[M].Shanghai:Shanghai Jiao Tong University Press,2000:172-210.
 张继祥.金属机械性能试验实用手册[M].北京:机械工业出版社,1986:159-163.ZHANG J X.Practical manual of metallic mechanical properties testing[M].Beijing:China Machine Press,1986:159-163.