抗HIC压力容器用Q345R(R-HIC)钢焊接接头组织与性能研究
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摘要
研发了抗HIC(Hydrogen Induced Cracking,氢致开裂)压力容器用Q345R(R-HIC)钢,并研究其焊接接头区域的显微组织及性能。结果表明,焊缝区、熔合区和热影响区显微组织主要由铁素体、贝氏体和珠光体组成。各区域热力学过程不同,焊接后显微组织存在明显差异:焊缝区显微组织主要由先共析铁素体、针状铁素体和粒状贝氏体组成;熔合区显微组织中贝氏体逐渐增多,铁素体逐渐减少;热影响区中的粗晶区显微组织几乎全部由贝氏体组成,细晶区和不完全重结晶区显微组织为等轴铁素体和珠光体组织。焊接接头具有良好的力学和抗氢致开裂性能。焊接接头微区硬度和冲击性能与显微组织关系密切:热影响区存在贝氏体组织导致其平均硬度最高、冲击功最低;针状铁素体具有良好的抗裂纹扩展能力,使得焊缝区具有良好的冲击韧性,冲击功最高。各区域差异的显微组织未对抗氢致开裂性能造成影响。
The Q345R(R-HIC) steel for anti-HIC pressure vessel was developed and the microstructure and properties of its welded joint were studied. The results show that the microstructure of weld zone, fusion zone and HAZ(heat affected zone)are mainly composed of ferrite, bainite and pearlite. As a result of different thermodynamic process during welding, the microstructure reveals obvious difference. Moreover,the microstructure of weld zone is mainly composed of proeutectoid ferrite, acicular ferrite and granular bainite. In fusion zone, the bainite increases, while the ferrite reduces. The microstructure of CGHAZ(coarse grain heat affected zone) is almost entirely composed of bainite. Furthermore, the microstructure of fine-grained zone and incomplete recrystallization zone are composed of equiaxed ferrite and pearlite. The welded joints have excellent mechanical property and anti-hydrogen induced cracking performance. The micro-hardness and impact properties of welded joints are closely related with the microstructure. The bainite in HAZ results in the highest hardness and the lowest impact energy of this zone. Meanwhile, the acicular ferrite in weld zone which has good anti-HIC ability leading to highest toughness. The anti-hydrogen induced cracking performance is insensitive to microstructure.
The Q345R(R-HIC) steel for anti-HIC pressure vessel was developed and the microstructure and properties of its welded joint were studied. The results show that the microstructure of weld zone, fusion zone and HAZ(heat affected zone)are mainly composed of ferrite, bainite and pearlite. As a result of different thermodynamic process during welding, the microstructure reveals obvious difference. Moreover,the microstructure of weld zone is mainly composed of proeutectoid ferrite, acicular ferrite and granular bainite. In fusion zone, the bainite increases, while the ferrite reduces. The microstructure of CGHAZ(coarse grain heat affected zone) is almost entirely composed of bainite. Furthermore, the microstructure of fine-grained zone and incomplete recrystallization zone are composed of equiaxed ferrite and pearlite. The welded joints have excellent mechanical property and anti-hydrogen induced cracking performance. The micro-hardness and impact properties of welded joints are closely related with the microstructure. The bainite in HAZ results in the highest hardness and the lowest impact energy of this zone. Meanwhile, the acicular ferrite in weld zone which has good anti-HIC ability leading to highest toughness. The anti-hydrogen induced cracking performance is insensitive to microstructure.
引文
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[5]王志刚,宋浩,胡广岐.不同热处理制度对Q345R(HIC)焊接接头组织及性能的影响[J].石油化工设备,2014,43(6):6-9.
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[8] Bhadeshia H K D H. Bainite in steels:Transformation,microstructure and properties[D]. Cambridge:University of Cambridge, 2001.
[9]杜楠,叶超,田文明,等. 304不锈钢点蚀行为的电化学阻抗谱研究[J].材料工程,2014(6):68-73.
[10]张德勤,雷毅,刘志义.微合金钢焊缝金属中的针状铁素体[J].石油大学学报,2003,27(4):141-145.
[2] Bhadeshia H K D H. Reliability of weld microstructure and properties calculations[J]. Welding Journal, 2004, 83(9):237-243.
[3]张鹏,赵国仙,毕宗岳,等.夹杂物和带状组织对管线钢腐蚀性能的影响[J].热加工工艺,2014,43(18):34-38.
[4]王磊. Q345(R-HIC)钢焊接接头的氢致开裂和应力腐蚀试验研究[D].镇江:江苏科技大学,2014.
[5]王志刚,宋浩,胡广岐.不同热处理制度对Q345R(HIC)焊接接头组织及性能的影响[J].石油化工设备,2014,43(6):6-9.
[6]黄安国,王永生,李志远.低合金钢焊缝中先共析铁素体组织数量的控制[J].电焊机,2003,33(10):9-14.
[7] Zhang Z, Farrar R A. Role of non-metallic inclusions in formation of acicular ferrite in low alloy weld metals[J]. Materials Science and Technology, 1996, 12(3):237-260.
[8] Bhadeshia H K D H. Bainite in steels:Transformation,microstructure and properties[D]. Cambridge:University of Cambridge, 2001.
[9]杜楠,叶超,田文明,等. 304不锈钢点蚀行为的电化学阻抗谱研究[J].材料工程,2014(6):68-73.
[10]张德勤,雷毅,刘志义.微合金钢焊缝金属中的针状铁素体[J].石油大学学报,2003,27(4):141-145.