冷拔无缝钢管据有很好的抗腐蚀性,冷拔无缝钢管的理化性能主要取决于钢的化学成分,组织结构和钢的纯净度以及冷拔无缝钢管的热处理方式等,冷拔无缝钢管常见的工艺性能压扁、扩口、卷边、弯曲、焊接等。冷拔无缝钢管常见的缺陷问题有:
The physical and chemical properties of cold-drawn seamless steel pipe mainly depend on the chemical composition of the steel, the structure and purity of the steel, and the heat treatment method of the cold-drawn seamless steel pipe. The common technological properties of cold-drawn seamless steel pipe are flattening, flanging, bending and welding. Common defects of cold-drawn seamless steel tubes are as follows: a. 危险性缺陷:裂纹、内折、外折、轧破、离层、结疤、拉凹、凸包等。
A. Dangerous defects: cracks, internal folding, external folding, rolling, delamination, scarring, concave drawing, convex hull, etc.
b. 一般性缺陷:麻坑、青线、划伤、碰伤、轻微的内、外直道、辊印等。
B. General defects: pits, green lines, scratches, bruises, slight internal and external straight paths, roll prints, etc.
缺陷问题产生原因:
The causes of defects are as follows:
① 由于管坯的表面缺陷或内部缺陷所带来的。
It is caused by the surface or internal defects of the billet.
② 生产过程中产生的,如轧制工艺参数设计不正确,模具表面不光滑,润滑条件不好,孔型设计及调整不合理。
(2) During the production process, such as incorrect design of rolling process parameters, non-smooth surface of die, poor lubrication conditions, unreasonable pass design and adjustment.
③管坯(冷拔无缝钢管)在加热轧制,热处理以及矫直过程中,如果因为加热温度控制不当,变形不均匀,加热冷却速度不合理或矫直变形量太大而产生过大的残余应力,那么也有可能导致冷拔无缝钢管产生表面裂纹。
(3) During hot rolling, heat treatment and straightening of cold-drawn seamless steel tube, if excessive residual stress occurs due to improper control of heating temperature, uneven deformation, unreasonable heating and cooling speed or excessive straightening deformation, surface cracks may also occur in cold-drawn seamless steel tube.
目前冷拔无缝钢管常见的缺陷问题已经在很大程度上进行解决,后续还是要多从钢材的工艺上下手,才能在后续的发展过程中取得一个较好的发展。
At present, the common defects of cold-drawn seamless steel tube have been solved to a great extent. In order to achieve a better development in the follow-up process, it is necessary to start with the steel technology.