晶粒粗大

结果表明，由于原材料晶粒粗大，导致材料的低温冲击韧度非常低，在偏载和换级时的冲击载荷导致液压缸断裂失效。

The results show that fracture failure is resulted from the coarse grain size of raw materials which causes very low impact toughness at low temperature ; when eccentric loading and impact load stage changing , it leads to the cylinder cracking .

当固溶温度分别为1100℃和1150℃时，合金几乎为单相F组织，晶粒粗大（1～2级），从而使合金的塑性和韧性稍有降低。

When the temperature is at 1100 ℃, or 1150 ℃, the microstructure of the alloy is almost all ferritic phase ( bcc ), with coarse grain ( level 1-2 ), so to made the plasticity and ductility decline slightly .

众和中Fe原子在基体中的不均匀分布，导致其高压箔的晶粒粗大、腐蚀不均匀，进而会降低了腐蚀箔的比电容。

Fe atoms in Join world and its uneven distribution of the matrix , resulting in high voltage aluminum foil thick grains , uniform corrosion , and thus reduce the capacitance of etched foil .

研究发现，传统工艺获得的炮弹式铸锭晶粒粗大，富钕相分布相对集中，还有αFe偏析；

It is found that the grains of shell-like ingots obtained by using traditional techniques are thick , the distribution of Nd-rich phases is relatively centralized , and there exists partial precipitation of α - Fe .

HAZ晶粒粗大、硬度高，局部腐蚀倾向大，由此导致该区SSCC敏感性高。

In HAZ , crystalline particles are coarse and has high hardness and is apt to cause local corrosion , thus it is a high SSCC sensitive area .

研究结果表明：1.Cr-Mn-N系高氮钢铸锭晶粒粗大，认为是Mn含量过高，C、N原子扩散速度快导致高温下晶粒长大迅速。

The results of the study indicate that : 1.Cr-Mn-N high nitrogen steel casting ingot has coarse grains , it is due to the high atomic diffusion speed of high content of Mn , C and N in high temperature .

1850℃真空烧结4h的YAG陶瓷晶粒粗大，晶界宽化，晶界处有共晶相YAlO3相和α-Al2O3相存在。

Large crystal grain and wide grain boundaries were obtained in YAG ceramics sintered at 1 850 ℃ for 4 h , and a eutectic region of yttrium aluminum phase and α - Al2O3 existed in the grain boundary .

结果表明：铸态含Mn合金的晶粒粗大，而含Zr合金的晶粒细得多，Zr能有效地细化Mg-RE合金的晶粒；

The results show that the grains of the alloy containing Mn at as-cast state are coarser and those of the alloy containing Zr are much finer , which obviously demonstrates grain refining effect of additional element Zr on Mg-RE alloys .

低熔点的Sn-Pb合金空心管坯连铸模拟实验表明，连铸管坯存在表观质量差、缺陷多、凝固组织晶粒粗大且周向分布均匀性差等问题。

The experimental results of continuous casting of hollow tubes showed that there were many problems such as poor surface quality , too many faults , and coarse crystalline grains in solidification structure and poor uniformity of structure in the circumferential direction .

铸轧带坯晶粒粗大的原因分析及对策

Cause Analysis and Strategy of Coarse Grain on Cast-rolling Strip

硬线盘条组织中局部晶粒粗大原因分析

Cause Analysis of Local Grain Coarsening in Hard Wire Rod

挤压铝合金板材避免晶粒粗大的工艺

Technology for avoiding coarse grain in aluminum alloy extrusion plates

其二是粗晶区晶粒粗大导致韧性下降。

The other is that coarse grains decrease the toughness .

卷扬机传动轴的断裂为典型的低应力脆断事故，主要原因是传动轴的组织疏松、晶粒粗大、。

The failure of the driving shaft in a hoister is caused by typical brittle fracture under low stress .

结果表明，材料的原始晶粒粗大是产生裂纹的主要原因。

The results showed that the cracking on fish plate was mainly resulted from the grain coarsening of material .

而传统工艺制造的合金通常会导致微观组织的晶粒粗大所以机械性能较差。

Conventional techniques of processing of alloys lead to a coarse-grain microstructure and give rise to inferior mechanical properties .

铸态镁合金的晶粒粗大，影响了其性能的提高和后续的应用。

The coarse grains in as-cast magnesium alloys have great effect on the improvement of their performance and applications .

研究发现，焊缝组织晶粒粗大，有新相Ni3Ti和Ti2Ni的析出；

Results show that the crystal grain in welded joint is large , and new phases such as Ni_3Ti and Ti_2Ni separate out .

但生产过程中常出现力学性能波动、晶粒粗大等问题。

However , during the practical process of production , there existed the fluctuation of mechanical properties and abnormal coarsening of some grains .

机架的常见缺陷有裂纹、掉砂、夹渣、缩孔缩松和晶粒粗大等。

The common defects of the housing casting include cracks , sand drop , slag inclusion , shrinkage porosity and rough grain , etc.

过长的烧结时间，将使β－Si3N4晶粒粗大，因而其性能降低。

When the holding time is too long , the β - Si 3N 4 grains become coarse and the properties will decrease .

晶粒粗大及晶间网状铁素体强烈降低材料的裂纹扩展阻力，并极易导致裂纹的失稳扩展。

Coarsening grain and intercrystalline network ferrite depress crack growth resistance of the materials strongly and result in unstable propagation of crack very easily .

但是由于冷速较低，结果晶粒粗大，晶界形成了粗大的碳化物网络，使得它在室温下为脆性，其延伸率几乎为零，机加工性能极差。

But it is brittle at room temperature because of its big grains and carbide network in the grain boundary coming from its slow cool-speed .

在直轧中，微合金化具有更好的效果，不足之处是初始晶粒粗大和压缩比较小。

It is found that microalloys have higher efficiency in direct rolling , but coarse initial grain size and lower reduction ratio are its shortcomings .

由于铝合金消失模铸态组织晶粒粗大、针孔严重、铸件力学性能较低，制约了铝合金消失模铸造技术的发展。

However , the LFC defects of aluminum alloy including coarse grains , serious pinholes and low properties greatly limit the development of LFC aluminum alloy technology .

适当降低挤压温度，出口温度控制在490～510℃，加强出口淬火强度，抑制晶粒粗大，有利于焊合线条纹的改善。

Decreasing the extruding temperature , controlling the outlet operating temperature between 490 ~ 510 ℃ and enforcing the outlet quenching can improve the welding mark situation .

在铸造过程中容易产生各种铸造缺陷，如晶粒粗大、缩孔缩松、开裂、组织和成份偏析等。

It is liable to produce various casting defects , such as coarse grain , shrinkage cavity , shrinkage porosity , hot tearing , microstructure segregation and solute segregation .

但由于其具有密排六方的晶体结构，室温下难以发生塑性变形，高温下又易发生晶粒粗大和表面氧化。

Due to hexagonal crystal structure , magnesium alloys have relatively low plasticity at room temperature while coarse grains and surface oxidation are prone to occur at elevated temperature .

结果表明，材质不良&晶粒粗大、素体沿晶界呈网状分布是导致螺杆断裂的主要原因。

It was revealed that the fracture of the bolt came from its poor quality including coarse grains and network-like distribution of ferrite along the grain boundaries of original austenite .

过高的烧结温度导致材料晶粒粗大，容易滋生裂纹，最终使复合材料抗弯强度的降低。

When sintering temperature is too high , which induced crystal grain grown up and the crack is easy to produce . Finally make the bending strength of composites reduced .