判断题
发布日期:2020-12-11
对
错
珠光体是铁素体和渗碳体一起组成的机械混合物用符号“P”表示。碳素钢中珠光体组织的平均碳含量约为0.77% 。它的力学性能介于铁素体和渗碳体之间,即其强度、硬度比铁素体显著增高,塑性、韧性比铁素体要差,但比渗碳体要好得多。珠光体是由奥氏体发生共析转变同时析出的,铁素体与渗碳体片层相间的组织,是铁碳合金中最基本的五种组织之一。代号为P。是由发现者名字命名。(珠光体组织呈指纹状,其中白色的基底为铁素体)
对物体施加外力,当外力较小时物体发生弹性形变,当外力超过某一数值,物体产生不可恢复的形变,这就叫塑性形变。塑性即物体变形的能力。与之相对的,对一物体施加外力,物体产生形变,移除外力,发现形变消失,物体恢复原样,这就是弹性,弹性越大的物体,能够承受越大的外力而不发生永久形变。而通常塑性越大的物体,能发生永久形变所需的最小力越小。
硬度,物理学专业术语,材料局部抵抗硬物压入其表面的能力称为硬度。固体对外界物体入侵的局部抵抗能力,是比较各种材料软硬的指标。由于规定了不同的测试方法,所以有不同的硬度标准。各种硬度标准的力学含义不同,相互不能直接换算,但可通过试验加以对比。
题王网让考试变得更简单
扫码关注题王,更多免费功能准备上线!
此试题出现在
把水煮沸是为了()。
Visitors to the zoo usually pity the animals owing to their particular emotional associations(联想). Which animals should be indeed pitied? The first type are those clever and 56 developed animals 57 lively intelligence and desire for activity can 58 no outlet behind the bars of the cage. Those animals living in a free state before 59 in the zoo have a strong desire for moving about 60 , but have to turnaround repeatedly in their quarters. Owing to this disappointment, foxed and wolves 61 in places which are far too small, are among the most 62 0f all zoo animals.Another sad scene, seldom 63 by ordinary zoo visitors, is the 64 flying trials of swans (天鹅 ) at migration (迁徙 ) time. These creatures, like most other water birds, are generally made unable to fly by the 65 0f cutting off a tip of the wing bone. 66 such swans in the zoo generally seem happy under 67 care and they raise their young without any trouble, at migration time things become 68 . The birds never really 69 that they can no longer fly, and repeatedly swim to the 70 of the pond so that they can have the whole extent of its surface when trying to 71 against the wind. Meanwhile, their loud flying calls can be heard as they try to 72 , and again and again the grand preparations end in 73 .I do not like seeing those 74 water birds in the zoo. The missing tip of one wing and the still sadder picture that the bird makes when it 75 its wings hurt me badly. What a truly sorry picture it is. 56 A high B highly C deep D deeply 57 A whose B whom C that D which 58 A find B lose C declare D transform 59 A to be put B being put C to put D putting 60 A partly B highly C deeply D freely 61 A kept B keeping C rose D rising 62 A victorious B thoughtful C miserable D fortunate 63 A scattered B written C noticed D wakened 64 A similar B suitable C apparent D constant 65 A experiment B operation C treatment D movement 66 A Although B When C Since D Because 67 A original B proper C parallel D precious 68 A private B public C different D similar 69 A suggest B assure C underline D realize 70 A limit B side C middle D center 71 A take off B stand up C take up D stand by 72 A spring B raise C swell D rise 73 A passage B support C failure D success 74 A upright B powerful C valuable D unlucky 75 A spreads B strengthens C enlarge D inspects
液限,塑限试验中,制备土样时过()mm筛。压缩,剪切试验中,制备土样时过()mm筛。
临床上癫痫发作与假性癫痫发和的主要鉴别为发作时有()
说托尔斯泰是俄国革命的镜子,是机械的直观的反映论。
患者男,4岁。诉发音不清求治,口腔检查:舌不能自由前伸,伸舌时舌尖部呈“M”形,智力发育正常。进行正确治疗的最佳时间是()。
一种产品的供给是直线且通过原点时,该产品供给()
出自明代陈实功《外科正宗》的内容是()
下列哪些是室性心动过速的心电图特征( )
以下选项中不属于受压构件中箍筋的作用是()
暂无相关推荐~
珠光体的片间距越小,强度、硬度越高,但塑性越差。
影响珠光体片间距的因素有哪些?
珠光体的片层间距随着过冷度的增加而()
按渗碳体的形态,珠光体分为()珠光体和()珠光体两种。
片状珠光体依片间距不同,可以分成()、()、()三种。
试定性说明珠光体生长速度和片层间距与过冷度、界面能和扩散系数的关系。
T10钢经过何种热处理能获得下述组织: (1)粗片状珠光体+少量球状渗碳体(2)细片状珠光体(3)细球状珠光体(4)粗球状珠光体
根据Fe-Fe 3C相图,计算: 1)室温下,含碳0.6%的钢中珠光体和铁素体各占多少; 2)室温下,含碳1.2%的钢中珠光体和二次渗碳体各占多少; 3)铁碳合...
根据 Fe-Fe 3C相图,计算: 1)室温下,含碳0.6%的钢中珠光体和铁素体各占多少; 2)室温下,含碳1.2%的钢中珠光体和二次渗碳体各占多少; 3)...
岸间距越小,岸壁效应越明显;船岸间距达()倍船宽时,便可显出岸壁影响。