Modification of MnS inclusion by tellurium in 38MnVS6 micro-alloyed steel

In 38MnVS6 steel, the morphology of sulfide inclusion has a strong influence on the fatigue life and machinability of the steel. In most cases, the MnS inclusions show strip morphology after rolling, which significantly affects the steel quality. Usually, the MnS inclusion with a spherical morphology is the best morphology for the steel quality. In the present work, tellurium was applied to 38MnVS6 micro-alloyed steel to control the MnS inclusion. Trace tellurium was added into 38MnVS6 steel and the effect of Te on the morphology, composition, size and distribution of MnS inclusions were investigated. Experimental results show that with the increase of Te content, the equivalent diameter and the aspect ratio of inclusion decrease strikingly, and the number of inclusions with small aspect ratio increases. The inclusions are dissociated and spherized. The SEM-EDS analysis indicates that the trace Te mainly dissolves in MnS inclusion. Once the MnS is saturated with Te, MnTe starts to generate and wraps MnS. The critical Te/S value for the formation of MnTe in the 38MnV6 steel is determined to be approximately 0.075. With the increase of Te/S ratio, the aspect ratio of MnS inclusion decreases and gradually reaches a constant level. The Te/S value in the 38MnVS6 steel corresponding to the change of aspect ratio from decreasing to constant ranges from 0.096 to 0.255. This is most likely to be caused by the saturation of Te in the MnS inclusion. After adding Te in the steel, rod-like MnS inclusion is modified to small inclusion and the smaller the MnS inclusion, the lower the aspect ratio.

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Research on Product Platform Innovation and Evolution Based on Lifecycle

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.431-432.82 ◽

2010 ◽

Vol 431-432 ◽

pp. 82-85 ◽

Cited By ~ 1

Author(s):

Liang Hou ◽

Hao Lun Wang ◽

Yu Yi Liu

Keyword(s):

Aspect Ratio ◽

Heat Pipe ◽

Relative Position ◽

Structural Parameters ◽

Experimental Results ◽

Groove Width ◽

Equivalent Diameter ◽

Product Platform ◽

Rake Face ◽

Spinning Process

Based on the principle of spinning process of micro grooves inside the circular micro heat pipe, the effects of relative position of balls and tool on the formation of micro grooves were investigated in this work. Experimental results showed that the relative position of balls and tool and ball equivalent diameter generally determined the pattern of grooves, including groove width and depth. Micro grooves could be produced when suitable value of D was chosen and the rake face of tool was near to the center of balls. In the experiment, the largest aspect ratio of micro grooves were achieved with the conditions of D= 5.56mm, d=-3.293mm and v=5.08mm/s. And the structural parameters were w=135μm, h=154μm and k=1.141.

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Study on Behavior of Carbonitride in Nb Micro-Alloyed Steel in CC-HR Region

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.472-475.1889 ◽

2012 ◽

Vol 472-475 ◽

pp. 1889-1898

Author(s):

Zheng Hai Zhu ◽

Sheng Tao Qiu

Keyword(s):

Heat Transfer ◽

Continuous Casting ◽

Thermal History ◽

Distribution Density ◽

Simulation Experiment ◽

Alloyed Steel ◽

Equivalent Diameter ◽

Saturation State ◽

The Status ◽

Micro Alloyed Steel

As for the techno -interface of CC-HR region, the precipitation and dissolution of carbonitride in Nb micro-alloyed steel E36 were studied during continuous casting, roller conveying, stack cooling, heat-preserved and heating units in typical slab process flow by hot simulation experiment based on study of heat transfer. The results are as follows: Ti(C,N), and (Ti,Nb)(C,N) precipitate in turn in continuous casting and conveying. A few (Ti,Nb)(C,N) particles are not solid solute completely after heating. The precipitation of carbonitride is effected significantly by different cooling rate in conveying. When slab conveied at the rate of 6.00 °C/min and then cooled down to 600°C, the distribution density of carbonitride particles is higher, and the average equivalent diameter of carbonitride particles is smaller, some carbonitride particles distribute along the austenitic grain boundaries and the generation elements of carbonitride particles are under over-saturation state. When slab conveyed at the rate of 0.30 °C/min or 0.15 °C/min and then cooled down to 400°C, the distribution density of carbonitride particles is lower, and the average equivalent diameter of carbonitride particles is bigger, the carbonitride particles precipitate fully. The behavior of carbonitride in slab are effected by different thermal history in heating. The status of carbonitride is effected insignificantly by different thermal history after heating.

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Effects of Relative Position of Balls and Tool on the Formation of Axial Micro Grooves Inside Circular Micro Heat Pipe during Spinning

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.431-432.70 ◽

2010 ◽

Vol 431-432 ◽

pp. 70-73

Author(s):

Min Qiang Pan ◽

De Huai Zeng ◽

Xiao Qing Liu ◽

Yong Tang

Keyword(s):

Aspect Ratio ◽

Heat Pipe ◽

Relative Position ◽

Structural Parameters ◽

Experimental Results ◽

Groove Width ◽

Equivalent Diameter ◽

Rake Face ◽

Micro Heat Pipe ◽

Spinning Process

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Fabrication of Nanoscale Vias by Offset Patterning

2008 Second International Conference on Integration and Commercialization of Micro and Nanosystems ◽

10.1115/micronano2008-70131 ◽

2008 ◽

Author(s):

Chi Ho Lau ◽

S. W. Ricky Lee

Keyword(s):

Aspect Ratio ◽

Oxide Layer ◽

High Aspect Ratio ◽

Experimental Results ◽

Width Ratio ◽

Equivalent Diameter ◽

Multiple Exposure ◽

Offset Distance ◽

Exposure Patterns ◽

Degree Of Overlap

Patterning of features with photolithography technique by overlying multiple exposure patterns with intentional offset reduces the effective size of the resultant opening when the openings overlap incompletely. The size of resultant opening depends on the size of the parental opening and the degree of overlap. Overlapping via patterns helps to achieve small via size from photolithography. In the present study, two oxide layers with via pattern were involved. The bottom oxide layer was deposited and patterned first. The top oxide layer and the poly-Si sandwich layer were then deposited on the patterned bottom oxide layer and patterned with an offset afterwards. Experimental results show resultant vias with size reduction by more than 50% compared with the parental vias. The equivalent diameter of the resultant vias goes down to as small as 400 nm. It was found that the equivalent diameter decreases with reduction in parental via size. The length-to-width ratio of the resultant vias opening increases as the parental via size becomes larger. The offset distance is also found to contribute significant effect to the size of the resultant via. The large offset distance leads to small but high-aspect ratio resultant vias.

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