加氢反应器壁材料的氢损伤特性  

CHARACTERISTICS OF HYDROGEN DAMAGES FOR HYDROGENATION REACTOR WALL-MATERIALS

作　　者：徐坚[1] 钟曼英[1] 郭世行[1] D Hardie 

机构地区：[1]中国计量学院机械与电子工程分院,杭州310034 [2]英国纽卡斯尔大学机械,材料与制造工程系

出　　处：《中国腐蚀与防护学报》2003年第3期149-155,共7页Journal of Chinese Society For Corrosion and Protection

基　　金：浙江省自然科学基金资助 ( 5 980 2 3 )

摘　　要：研究了在模拟加氢反应器工况条件下 ,国产加氢反应器壁材料 [2 (1/ 4 )Cr - 1Mo及其上的 30 9L和 347L不锈钢堆焊层 ]的氢损伤特性 .结果表明 :热渗氢后 ,明显降低了它们的断裂应力 (σf)和塑性 .对于 30 9L和 347L堆焊层 ,未经热渗氢的原始试样 ,无论是光滑试样还是缺口试样 (除缺口位置在 30 9L区域试样外 )均断裂在 347L区域内 .而经热渗氢后 ,无论是起裂于 2 (1/ 4 )Cr - 1Mo和 30 9L的熔合线 ,还是 30 9L和 347L的熔合线处 ,最后都断在30 9L区域内 (除缺口位置在 347L区域试样外 ) .这是因为热渗氢使 30 9L和 347L的σf 分别从原始状态的 885MPa降至 4 78MPa和从原始状态的 799.9MPa降至 5 6 4MPa ;在对短裂纹的低周疲劳特性研究中 ,用da/dN =C(ΔJ) n计算了裂纹扩展速度 (da/dN)和门槛值 (ΔJth) .经热渗氢后 ,ΔJth有明显的下降 ,da/dN～ΔJ曲线也向左移 ,提高了da/dN .SEM断口分析结果与上述结论一致 .裂纹扩展以穿晶为主 ,热渗氢后有二次裂纹存在 .说明热渗氢降低了其力学性能 。The characteristics of hydrogen damages for hydrogenation reactor wall-materials,which include the structure material of 2(1/4)Cr-1Mo and the weld overlay cladding of 309L and 347L,in original and hydrogen charged had been investigated.The results of slow strain rate testing(SSRT)indicated that ⅰ)Fracture stress and plasticity decrease obviously after thermal charging of hydrogen.ⅱ)For original specimens the fracture of both smooth and notched specimens occurred in the 347L region(except the specimen which notched in 309L region),but if specimens charged with hydrogen the fracture changed in 309L region(except the specimen which notched in 347L region).Because after thermally charging with hydrogen the fracture stress dropped from 885 MPa to 478 MPa for 309L and from 799.9 MPa to 564 MPa for 347L respectively.The characteristics on low frequency fatigue with short-crack had been investigated.The formula d a /d N = C (Δ J ) n was used to calculate the propagation rate(d a /d N )in three stages and the conditional threshold value(Δ J th )of the fatigue crack.The results showed that the Δ J th of specimen after thermal hydrogen charged dropped obviously and the d a /d N increased.In addition,the fracture morphology of SSRT and different crack propagation mechanism of low frequency fatigue in three propagation stages had been observed by SEM.

关 键 词：承载材料 堆焊层 热渗氢 SSRT 低周疲劳 

分 类 号：TG113.25[金属学及工艺—物理冶金]