鞍钢无缝钢管厂φ100毫米无缝钢管机组二辊斜轧穿孔机轧出的荒管,经常在距后端约300毫米处出现直径变小、壁厚变薄的“细脖”现象,在穿轧薄壁管时这种现象尤为严重。1978年鞍钢无缝钢管厂由于“细脖”而切去的管头总量达500—600吨(包括正常切头)。由于“细脖”处的直径与壁厚都超出负偏差,必须切除,因而直接影响钢管产量和质量的提高。一旦荒管上出现“细脖”,就得停机 Anshan Iron and Steel Seamless Steel Tube Plant φ100 mm seamless steel pipe rolling mill crossed the second barrages shortage of pipe, often at a distance of about 300 millimeters from the rear end appears smaller diameter, thinning thinning “thin neck” phenomenon, wear This phenomenon is particularly serious when thin-walled tubes are rolled. In 1978, Angang seamless steel pipe factory cut a total of 500-600 tons of pipe heads (including normal cut heads) due to “thin necks”. As the “thin neck” at the diameter and wall thickness are beyond the negative deviation, must be removed, and thus directly affect the steel production and quality improvement. Once barren tube appears “thin neck”, you have to shut down