中心疏松

该系统优化之后杜绝了表面纵裂及横裂，中心疏松及偏析明显改善，消除了内部裂纹。

After optimization , we can prevent surface longitudinal and transverse cracks , improve center porosity and segregation , and eliminate internal cracks .

研究了连铸中包钢水过热度、铸坯末端电磁搅拌参数与连铸坯中心疏松、缩孔、碳偏析及等轴晶率的关系。

Tis paper describes the effect of superheat temperature of molten steel in tundish , solidification end electromagnetic stirring parmeters on the equiaxed crystal zone and slab defects , such as center porosity , shrinkage cavity , carbon segregation , etc.

浇注工艺对连铸坯中心疏松的影响

The effect of CC process parameters on central porosity of billet

铸坯表面无纵裂、横裂等与二冷配水相关的质量缺陷，铸坯中心疏松1.0级，中心缩孔0～0.5级。

The billet center porosity is 1.0 , and the center line shrinkage is 0 ~ 0.5 .

压圈原材料中心疏松及锭型偏析是导致裂纹形成的主要原因。

The results showed that central porosity and ingot shape segregate were the major causes of the cracking .

结果表明，锻坯原材料中存在的中心疏松和氧化物夹渣等低倍缺陷是导致锻件开裂的主要原因。

The results showed that the oxidation slag inclusion and central porosity in the raw material were the direct reasons which the forging cracking .

减少中间包钢水过热度，采用铸模电磁搅拌和低速浇铸等可防止柱状晶裂纹和减少中心疏松和偏析。

The columnar zone crack could be prevented and the centre porosity and segregation decrease by decreasing superheat of metal in tundish , using electromagnetic stirring and low casting velocity .

电磁搅拌是改善铸坯凝固组织、扩大等轴晶区降低宏观偏析减轻中心疏松和缩孔、减少裂纹等凝固缺陷的一项很有效的凝固控制技术。

Electromagnetic stirring ( EMS ) is an effective solidification control technique of improving the solidification structure , expanding equiaxed zone and eliminating macrosegregation and reduce center cavitation and crack .

结果表明，连铸方坯上的中心疏松、中间裂纹和中心裂纹颇为严重，分析认为这些缺陷是浇注温度、冷却强度和拉坯速度等因素综合影响的结果。

Results indicate that the continuous casting billets have serious defects such as centre porosity , interal cracks and centre cracks , caused by the combined effects of improper casting temperature , cooling intensity , casting speed and so on .

结果得出：螺钉在扭力试验过程中断裂是由于内部存在严重的孔洞和孔隙所造成的，孔洞和孔隙来源于原铸坯的中心疏松。

Results indicate that the primary cause to the rupture of the screw in the process of torque force test is proved to be heavily existence of holes and pore gaps in the screw arising from the central looseness of the original billet .

连铸坯中心偏析和疏松缺陷在轧制过程中的形态演化

Pattern Evolvement of the Central Segregation and Looseness of the Continuous Casting Billet in Rolling Process

凝固末端动态轻压下技术是减少甚至消除连铸坯中心偏析与疏松的有效手段。

The dynamic soft reduction technology is the effective method to reduce and even eliminate the centerline looseness and segregation of continuous casting strands .

最致密的木材在树干外围，这里的抗折压力是最大的，而树干中心的木质疏松多孔，比重更小。

The densest wood is on the outside , where bending stress is the greatest , while the center is porous and weighs less .

动态轻压下技术可以显著改善连铸坯的中心偏析和疏松，已经成为提高连铸坯内部质量的先进技术之一。

As the one of advanced technologies for continuous casting process the dynamic soft reduction can significantly improve center segregation and porosity of continuous casting products .

且当搅拌电流从100A增大到300A时，中心偏析、中心疏松和缩孔等级明显降低。

The center segregation and porosity and the shrinkage cavity are obviously improved , when the stirring electric current rises from 100 A to 300 A.

预防小方坯中心偏析与中心疏松的措施

Countermeasures for Centerline Segregation and Central Porosity of Continuous Casting Billets

柔性辊轧成形轴类零件具有周期短、成本低、高柔性的特点，但中心材料容易产生疏松或孔腔等损伤缺陷。

The flexible rolling process is suitable for forming of the step shaft forgings , with the advantages such as short development period , lower cost and high flexibility .

分析了连铸薄板坯在冶炼及连铸过程中产生的表面夹渣、内部非金属夹杂，铸坯凝固过程中产生的表面裂纹、中心偏析及中心疏松等质量缺陷。

The quality defects of CC thin slab was analyzed , such as the surface included slag and no-metallic inclusions resulted from steelmaking and casting processes , the surface cracks and central segregation , central porosity caused by solidification of the slab .

但在高碳钢连铸中，往往容易产生中心偏析、V形偏析、中心疏松等问题。

But several defects are usually found in the continuous casting of steel , such as center segregation , V segregation and central porosity , especially for high carbon steels .

试验和生产应用表明，静态轻压下技术在高碳连铸方坯生产中应用，可降低铸坯中心碳偏析，改善铸坯中心疏松状况。

Both experiments and production practice have showed that the application of static soft reduction technology can decrease carbon segregation and improve looseness state in billet central area .