裂纹

The results show that the toughness of over-heated zone increased greatly because of austenite film lying in lathy martensite and a few ferrite.The toughness of fine grained zone decreased due to many factors,such as acicular martensite,a small quantity of austenite film,carbide separation and so on.

结果表明，10Ni8CrMoV这一新型钢种的模拟焊接热影响区的过热区和细晶区表现出与绝大多数材料完全相反的规律，过热区存在少量的铁素体组织，马氏体板条束之间形成了一定量的奥氏体薄膜，这些韧度相的存在使得过热区的冲击韧度与基体相比有了较大的提高；细晶区部位奥氏体含量很少，细小的板条马氏体端部呈针状特征造成应力集中，易于诱发裂纹。

Based on the properties of powdered metal compacting and fracture generation, a liminal energy condition of fracture generation in metal powder deformation process is suggested.

根据本文提出的金属粉末压制模型，推导出了基于细观损伤力学方法建立的粉末金属成形过程中裂纹出现的判据。

When mechanical negative charge is very big meshy hot crack expands very easily.

当机械负荷非常大时网状热裂纹很轻易扩展。

It was analyzed by means of metallographical examination, chemical composition analysis and inclusion testing, the results show that the fracture was mainly caused by no-metallic inclusion.

通过对层裂坯料进行宏、微观检验、化学成分和夹杂物分析，认为大颗粒硫化物夹杂及其富集破坏了基体的连续性，是镦制过程中产生裂纹的主要原因。

A nickel-based nano-WC/Co composite coating on 45 steel was gained with continuous wave CO_2 laser of 2.0 kW,the surface of which is smooth and fine without crack or pore and metallurgically bonds with matrix.

采用横流2.0 kW CO_2激光器，在45钢表面制备了表面较平整、较细密、基本消除了裂纹与孔隙并与基体呈冶金结合的镍基纳米WC/Co复合涂层。

The experimental results indicate that on the condition of Ni/C ,Zr added,the clad layers are metallurgically bonded to the substrate with fine shape and free of pores and cracks.

在楔横轧模具钢55Mn表面采用同轴送粉CO2激光熔覆WE—TiCp／镍基合金复合粉末，在增碳、锆条件下可获得成形好、无裂纹、与基体冶金结合的熔覆层。

Dense alloy coating without pore and inclusion is obtained which metallurgically bonded with steel but existing a few cracks. The results show that the cladding alloy coating is mainly composed of single-phase Fe3Al, and the microstructure is coarse equiaxed grain-groups that consist of large amount of fined slug like Fe3Al grains, between which some adjacent grains have the similar orientation.

试验获得了致密、无肉眼可见气孔、夹杂的合金层，合金层与基体间完全冶金结合，但存在裂纹现象；熔覆合金层主要由单相Fe3Al构成，覆层组织为粗大等轴状晶团，等轴状晶团由大量极细小的条状Fe3Al晶粒构成，一些相邻的条状晶粒之间具有基本一致的晶体学取向。

A Ni-Cu based cladding was thus deposited, where the powdered Ni1015 was provided for the laser cladding process to form a smooth surface layer bonded metallurgically with Cu substrate, whose grain-refining microstructure is homogeneous, compact, void-free and crack-free.

用5 kW CO2激光器，通过优化激光工艺参数，在结晶器用铜合金表面预置添加SiC晶须的镍基自熔合金(Ni1015)粉，制备出表面平整、组织均匀致密、无气孔和裂纹等缺陷、与基体为冶金结合的Ni-Cu激光熔覆层。

Based on linear elastic fracture theory, a damage evolution equation for composite soild propellant under uniaxial tension is derived. Main mecrosopic of material are determined through fittin the experiment data of constant rate tension. Then, the integrate constitutive equations found is close to microlevel.

基于线弹性断裂理论，提出了一个适合复合固体推进剂的脱湿微裂纹损伤发展方程，通过部分单向定速拉伸试验数据拟合确定其主要的细观参数，从而得到了复合固体推进剂在细观水平上完整且封闭的本构方程组。

The equilibrium phase particles that induce the sensitivity of the quenching are not the direct reason that causes the alloy fracture; the microzone of PFZ around particles limits crack extension and coordinates deformation, this causes the formation of the ductile tension fracture.

引起淬火敏感性的平衡相粒子，不是造成合金断裂的直接原因，粒子周围的无析出微区起到了限制裂纹扩展和协调变形的作用，是合金形成延性拉伸断口的原因。

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。