裂纹

One cause of delay in the development of new steels has been that welds have failed, causing cracking.

阻碍新钢材发展的一个原因是焊接曾遭到失败，产生了裂纹。

The dynamical processes of the nucleation and propagation of stress corrosion cracking of four low alloy steels with a wide range of tensile strengths in aqueous media with various polarization conditions, in a K_2Cr_2O_7 inhibitor solution and in some organic solvent such as acetone and alcohol were traced with an optical microscope.

用抛光的恒位移试样跟踪观察了具有广泛拉伸强度范围的四种低合金钢在各种水溶液中(高纯水、阳极极化和阴极极化下的水溶液，0.1NK_2Cr_2O_7水溶液)以及含痕量水的有机溶剂中应力腐蚀裂纹产生和扩展的动态过程。

The test result shows that fatigue crack rate in welding line area is greater than that in parent metal when crack stress intensity factor amplitude △K is greater than 20 Mpa,but there is no more difference.

试验结果表明，在应力强度因子幅△K＞20Mpa后疲劳裂纹在焊缝区的扩展速率比在母材的大，但两者差距并不悬殊。

At present, crack propagation life analysis depends on the Paris's formula, which needs the stress intensity factor amplitude function. In the engineering, the SIF function is simplified. A new method to determinate the function is put forward.

目前的机械结构裂纹扩展寿命分析方法主要是基于Paris公式的，它需要确定应力强度因子幅值的数学表达式，工程应用采用简化方法计算求得。

Based upon the experimental results, including threshold values under static loading,the effects of alternating loading and room temperature creep,as well as metallographic observations of the fractography,it is concluded that notwithstanding stress corrosion or corrosion fatigue in aqua ammoniae,or fatigue in air,the cracks always initiate at the site subject to maximum normal stress(θ=-110°)along the notched surface,and then propagate along the maximum shear stress direction from that site(α=-35°).

由门槛值的测量、交变载荷的作用、室温蠕变的影响、断裂过程的金相观察及断口形貌等结果，可以确认；黄铜不论是在氨水中应力腐蚀或腐蚀疲劳，还是在空气中疲劳，裂纹都从Ⅱ型缺口试样的最大正应力处(0=-110°)萌生，并沿该处的最大剪应力方向(α=-35°)扩展。

The results indicate that the CTOD values of welded joint are lower than those of all base plate of identical crack length.

结果表明，焊接接头的CTOD值均低於同裂纹尺寸的全母材。

Plate and beam is the element of over head traveling crane. Crack damage of plates and beams is the main fault forms of structure.

板和梁是冶金桥式起重机金属结构的基本组成单元，而这些金属结构的损伤多以板、梁的疲劳裂纹表现其故障形式。

By ultrasonic echo noise-reduction testing on CS-1-5 test block's flat bottom hole and certain helicopter totors' fatigue flaw, it is shown that ultrasonic signal SNR is increased remarkably.

经对CS-1-5试块的Φ2平底孔超声反射回波和某型直升机旋翼大梁疲劳裂纹超声反射回波的降噪试验，试验结果表明，处理后的超声信号信噪比显著增强。

The results show that, the microstructure of the boiler steel is unqualified and great stress appears on the surface of drum caused by boiler scale, so micro-crack appears and grows on the surface of boiler steel which leads to dehiscence.

结果表明：锅筒钢板组织不合格，同时锅垢还使锅筒钢板表面产生较大的应力，致使钢板产生显微裂纹并扩展，以至最后开裂。

The oxidation-deoxidization between Al and ZrO2 or Y2O3 is one of the mechanisms of high temperature oxidation failure of TBCs. The failure under thermal shock results from the formation of cracks normal to the bond/top coat interface, due to the different coefficients of thermal expansion between bond coat and top coat and the temperature change.

底层与面层之间界面存在的部分Zro，或YZO3被A1还原生成Zr或Y，A1被氧化形成A1203的反应是热障涂层高温氧化失效的原因之一；热震失效的主要原因是由于底层与面层之间热膨胀系数的差异而产生的剪应力与喷涂时产生的内应力之和导致面层产生裂纹。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。