裂纹

Mm. 7.5.3 Requirements for quality of weld joint's surface: a No crack, not fusional, bubble, slag, splash; b Surface of seam of pipeline with design temperature lower than -29℃, stainless steel pipeline and alloy steel pipeline with trend of harden quenching shall be free from undercut.

The surface shall be smooth 7.5.3 焊接接头表面的质量应符合下列要求： 28 SH 3501-2002 a 不得有裂纹，未熔合，气孔，夹渣，飞溅存在； b设计温度低于-29℃的管道，不锈钢和淬硬倾向较大的合金钢管道焊缝表面，不得有咬边现象；其他材质管道焊缝咬边深度不应大于 0.5mm，连续咬边长度不应大于 100mm，且焊缝两侧咬边总长不大于该焊缝全长的 10%； c 焊缝表面不得低于管道表面，焊缝余高Δh 应符合下列要求： 1 100%射线检测焊接接头，其Δh≤1+0.2b1，且不大于 2mm； 2 其余的焊接接头，Δh≤1+0.2b1，且不大于 3mm。

The trivalent chromium passivation film based on zincate plating obtained has compact structure with no obvious crack, and excellent anticorrosion performance. Different compositions are detected from the surface to inner film, the surface mainly contains Cr2O3-Cr3-ZnO compound, the inner (1030 nm to surface) composes of Cr2O3-ZnO-Zn.The forming process of passivation film possibly consists of four steps which are zinc dissolution, basic area appearance, gelatiniform film forming and converting to passivation film.

结果表明：锌酸盐镀锌层的三价铬钝化膜表面结构致密、无明显裂纹，具有较好的耐腐蚀性能；这种钝化膜表层与里层的组成不同，表层的组成为Cr2O3-Cr3-ZnO共混物；里层(离表层10~30 nm处)的主要组成为Cr2O3-ZnO-Zn共混物；钝化膜的成膜过程可能包括镀锌层的溶解、碱性薄层的形成、胶状膜的形成和胶状膜转化成钝化膜4个步骤。

Ductility dip cracking ; experiment method ; generant mechanism ; preventive measure

高温失塑裂纹；试验方法；产生机理；防止措施

GIM,on the one hand,is presented to simulate the interphase,and on the otherhand,is used to obtain the usual square-root singularity rather than the oscillatorysingularity near the crack tip.

本文所给出的广义界面层模型一方面模拟了界面相；另一方面消除了裂纹尖端附近的应力振荡奇异性。

The effect of the graphitic morphology on the produce and extension of the fatigue cracks has been discussed.

探讨了石墨对疲劳裂纹萌生及扩展的影响。

Mechanism of ductile fracture at corner of workpiece during grooveless rolling for high-speed wire is analysed in this paper.

分析了高速线材无槽轧制过程中轧件角部产生韧性断裂的机理，采用数值模拟方法研究了轧件角部出现裂纹的趋势。

The analysis of the application of grooveless rolling technology proves that grooveless rolling can be successfully realized in the big-distance mills.

通过对无孔型轧制的工业试验和技术分析，得出无孔型轧制可在大间距轧机上实现，脱方控制的关键点是导卫控制和宽展控制，翻平宽展能使轧件产生圆弧钝角，避免了应力集中和裂纹，采用无孔型轧制具有可统一坯料、提高轧辊寿命2～4倍、降低能耗6%～7%等优点。

The hydroscopic expansion coefficient of grains is an important physical parameter for prediction of bulk densities and study of internal stresses of grain kernel during adsorption and desorption.

湿膨胀系数用于预报谷物堆密度和研究谷粒应力裂纹产生原因等研究。

The feasibility of inner crack intercritieal heat treatmemt in hypoeutectoid steel was analysed in detail by metallurgical principle.

利用金属学原理，分析了亚共析钢内裂纹亚温愈合处理的可行性。

By the model of infinite flat with impenetration crack model, we calculate the frequency range of the electromagnetic radiation during several rock fracture which is from middle to high frequency.

通过建立具有中心贯穿裂纹的无限大平板模型，根据破裂宽度计算了在该模型条件下几种岩石破裂过程中产生电磁辐射频率范围。

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。