The main reasons causing increased chilling tendency of nodular iron are as follows : using metal charge containing trace and alloy elements which can increase chilling tendency ; molten iron being holded at high temperature too long ; abnormal nodularizing and / or inoculation treatment , as well as abnormal composition control 摘要引起球铁白口倾向大的主要原因是：炉料稳定性差、电炉保温、球化处理及铁液成分控制和孕育处理出现异常。
The effects of alloy elements nb , v , ti , re on mechanical properties , corrosion - abrasion resistance , fragility of ferritic stainless steel cr30mo have been investigated . the results show microalloy is beneficial to increas corrosion - abrasion resistance and suppress brittleness of cr30mo 研究了铌、钒、钛、稀土元素对不锈钢的组织结构、力学性能、磨蚀性能和脆性的影响，结果表明微合余化是提高铁素体不锈钢耐蚀性，降低脆性的有效途径。
It was reported in this paper that in the aes analysis of aluminum alloy ingots by the photoelectric direct reading spectrometer , segregation of alloying elements , especially silicon in the alloy was observed , leading to deviation of analytical results obtained from different site of excitation 摘要在用光电直读光谱仪分析铭合金时，在不同激发点所取得的合金元素的测定结果，特别是硅的刚定值，之间存在明显偏差，并证实系由合金的偏析所引起。
The high speed steel of composite roll is characteristic of high carbon and high alloy elements . so it is easy to form a lot of netlike carbides . these carbides which are very hard and fragile and are very difficult to be eliminated by heat treatment can depress the properties of high speed steel 复合轧辊用高速钢具有高碳和高合金的特征，容易形成大量网状碳化物，这些网状碳化物又硬又脆，会严重降低高速钢的性能，且难以用热处理的方法予以消除。
Result shows that the parameters of alternating electric field have marked effect on the electrochemical behavior of stainless steel , and the role of alloying element in stainless steel is different in the dissolution and deposition process 结果表明：电极电化学反应总量随着交变电场频率的升高而减少，随着占空比的增加出现峰值，随着高、低电位的绝对值的增加而增加同时对交变电场下电极表面各元素的选择性溶解进行了探讨，并通过电化学测试对研究结果进行了分析。
The production practice showed that , as along as adopting hi - quality ductile iron castings which has reasonable chemical composition including proper alloying elements and satisfactory as - cast structure , and adopting effective heat treatment process , the comprehensive mechanical properties of adi could be greatly increased and it was concluded that it is possible to produce high toughness adi castings with stable quality 生产实践证明：设计合理的化学成分，经过适当的合金化，铸造优质的球铁毛坯，采用有效的热处理工艺，可大幅度提高等淬球铁的综合力学性能，稳定生产高韧性等淬球铁铸件。
The following results are achieved : ( 1 ) in accordance with the empirical electron theory of solids and molecules , considering the number of covalent bond pairs on the strongest bond in a segregation structure na , the elements for matrix - strengthening can be chosen . ( 2 ) on the basis of the available phase - equilibrium thermodynamics calculation of alloy system and phase diagrams , which have been worked out , the contents of alloy elements can be identified with reference to the types , quantity and phase - transformation of carbides . ( 3 ) both the values relating to toughness ( including bending strength , yield strength , impact value of unnotched samples ) and hardness of new dm9 die steel are higher than those of crl2mov die steel 结果得出： ( 1 )根据固体与分子经验电子理论，利用偏聚结构单元的最强共价键上的共用电子对数n _ a ，可以选择工模具钢基体相的强化元素； ( 2 )根据合金系相平衡热力学计算及已有的相图，可以碳化物类型、数量及其相变确定合金元素含量； ( 3 )新型dm9钢在强韧性(抗弯强度、屈服强度、无缺口冲击值)和硬度方面均高于cr12mov钢； ( 4 )以dm9钢与6crw2si 、 7cr2wmovsi ( dm7 ) 、 h13和cr12mov四种模具钢的实验比较，进一步验证了上述冷作模具钢合金设计方案是合适的。
That the alloying element mn and ti substitutes the atom of fe in the rich iron - phase ( al , si , fe ) and resumes the part of the element si in primary phase refines the second phase . at the same time , the volume percentage of second phase is increased . at the course of solidification , the alternating current field changes obviously the microstructure morphology of the al - 20si - 5fe - x alloy and the number of particle eutectic structure is increased 合金元素mn 、 ti通过占据富铁相( al , si , fe )中铁原子的晶格位置，同时消耗部分初生相中的si元素，形成四元富铁相( al , si , fe , mn ) ，细化了合金中的第二相，同时提高第二相体积百分数。
Mixing alloy elements of ni , mo , w in fe - c - cu alloy , the sintered steel was prepared . the microstructure and wear resistance properties of the sintered steel had been studied . the influence of heat - treated technology and the alloy elements on the microstructure and the wear resistance had been studied and analyzed 以fe - c - cu合金为基粉，添加合金元素ni 、 mo 、 w制备烧结钢，并对试样进行了微观组织和耐磨性分析，系统地研究了热处理工艺及合金元素镍、钼、钨的复合添加对烧结钢组织和耐磨性的影响。
It is researched that the influence on the tube lifetime of the metallographic structure and the alloy element and the rigidity by the test the superheater and reheater tube which is made of 12cr2mowvtib steel . the metallographic change after the tube has run in the high temperature and high pressure condition for long time is more believable and frank than the intensity lifetime analysis to evaluate the tubes remain lift time 然后，通过试验研究了过热器和再热器管12cr2mowvtib钢材的金相组织、合金元素和硬度等对管道寿命的影响，分析管材在高温高压下长期运行后金相组织的变化情况，对管材定性寿命评估，这种与强度寿命分析完全不同的方法直观可信的展示了材料损伤状况。
