材料科学技术（英文）
Sulfide stress corrosion cracking (SSCC) behaviour of UNS G11180 steel in 5% NaCl solution with H2S was, studied by slow strain rate tensile test (SSRT), SEM and electrochemical hydrogen permeation technique. The results reveal different cracking mechanism and H permeation current (I-H) through UNS G11180 steel plate in different concentration of H2S solution. The susceptibility to SSCC of UNS G11180 steel in 5% NaCl solution with H2S was evaluated by the permeation current (I-H, mu A), which depends on the concentration (c x 10(-6)) of H2S by the equation: I-H = 8.525 x c(0.7249). It is proved that the electrochemical H permeation method is a practical way to assess the susceptibility to SSCC.
关键词:
cracking
H.Wang
,
S.L.Ogin
,
A.M.Thorne
,
G.T.Reed
材料科学技术（英文）
Polarimetric optical fibre sensors have been embedded within the 0℃ ply and close to the 0/90 interface of transparent cross-ply GFRP coupons. The laminate ply cracks may initiate and propagate across the coupon when the coupons were subjected to an increasing quasi-static load in a servo-hydraulic testing machine. Crack accumulation have been monitored using a long gauge-length extensometer. The response of the strain signal, the optical signal and the load signal to cracks at different positions in the coupon in relation to the extensometer and optical sensor positions have been acquired and compared by means of video images of the crack growth. The relationship between crack growth and sensor response was demonstrated. The displacement induced by a new transverse crack has been predicted and compared with experimental data.
关键词:
Matrix cracking
,
cracking
,
Polarimetric
,
sensor
,
Four
S.H. Dong
,
Y.M. Lu
金属学报(英文版)
Based on the theory of hydrogen enhanced localized plasticity of the hydrogen induced cracking and considered the effect of residual stress produced by eliminated stress heattreatment, a fractal model of hydrogen induced cracking was presented, and a relationship among the effective surface energy T( H), fractal dimension D and stress intensity factor of hydrogen induced cracking, KIH, for welding pipeline under hydrogen environment was set up, from which the relationship of D and KIsCC is obtained. The model was verified experimentally to be correct.
关键词:
hydrogen environment
,
null
,
null
,
null
,
null
张正法
钢铁
用作摩托车排气管的410S铁素体不锈钢焊管在弯曲成形时从焊接接头开裂,针对焊管弯裂的成因进行了试验分析,找出了弯裂原因为粗大的铁素体晶粒、马氏体及高温脆化引起的焊接接头塑、韧性降低,并提出了改善或避免该缺陷的措施,即适当加快焊接速度以减小焊接热输入量,使焊缝及热影响区变窄并降低铁素体晶粒的粗化倾向。
关键词:
铁素体不锈钢
,
焊接
,
开裂
,
金相组织
杨志勇
,
孙宇红
物理测试
分析了滚筒在筒皮和轮毂焊缝处断裂的原因,通过化学成分分析、硬度测试、显微组织观察、断口宏观观察和扫描电镜分析研究了断裂原因。结果表明：轮毂的化学成分符合国家标准,基体组织正常;筒皮中磷成分超过国家标准,基体的带状组织严重,达到了3级,在焊接热影响区形成魏氏组织,使焊缝的韧性急剧下降,焊接接头变脆,导致滚筒在焊缝处开裂。
关键词:
带状组织
,
魏氏组织
,
焊缝
,
开裂
刘荣桂
,
喻孟雄
,
姜慧
,
陆春华
硅酸盐通报
假定钢筋锈胀力呈椭圆形分布,将钢筋锈胀力分解为均匀钢筋锈胀力和偏差钢筋锈胀力,并利用弹性力学方法分别进行求解,得到相应的应力场和位移场理论解,再叠加得到非均匀锈胀的应力场和位移场解析表达式.以此为基础,提出了锈胀开裂时刻的钢筋锈胀力计算公式.模型探讨结果表明:混凝土内任意定点的应力场和位移场与钢筋锈胀力分布不均匀系数k成线性关系;锈胀开裂时刻的钢筋锈蚀率与k的线性函数成反比例关系.
关键词:
非均匀锈胀
,
开裂
,
钢筋混凝土
,
钢筋锈胀力
,
弹性力学理论
罗德信
,
蒋跃东
,
仇东丽
钢铁研究
结合生产合金钢线材时冷镦检验试样沿45°方向出现开裂的问题,在实验室作了检验分析。结果表明,冷镦开裂的原因是由于铸坯上存在成分偏析,在轧制中不能消除,遗传到线材上,形成轧后组织偏析,导致冷镦开裂。通过对试样偏析处的成分定量分析查明,合金钢线材偏析带的主要成分为Cr、Mn,偏析处的平均成分比正常部位成分分别高出49%和79%。
关键词:
连铸坯
,
中心偏析
,
冷镦试验
,
开裂
