本周北京镀锌方管价格小幅跟涨厂家操作积极…方管本周北京镀锌方管价格小幅跟涨，价格方面，截至2020年5月15日，其中方管4寸 （3.75mm）价格为4070元；镀锌方管4寸（3.75mm）利达产4980元，正金元产4790元，唐山京华产4740元，吉立（正大）产4740 元，君诚产4790元，天谊产4710元；比上周同期上涨20元。 据监测数据显示：截至2020年5月15日，唐山镀锌方管…

有时方管坯会出现分层问题，从而导致探伤不合。要预防这一缺陷，我们可以采取以下三点处理措施：(一)优化缓冷时间：优化方管板坯的缓冷工艺，主要针对堆垛温度和堆垛持续时间。轧制钢板厚度不大于80mm钢板热矫直后，在冷床停留时间不得超过5min。厚度大于80mm钢板可适当延长至10min，确保钢板成垛前温度控制在500℃以上。钢板厚度不大于50mm钢板缓冷时间在12h;厚度大于50mm的钢板缓冷时间24h，严禁提前拆垛精整。
Sometimes the stratification of square billet will occur, which will lead to incompatibility of flaw detection. To prevent this defect, we can take the following three measures: (1) Optimizing slow cooling time: optimizing slow cooling process of tube slab, mainly for stacking temperature and stacking duration. After hot straightening, the residence time in the cold bed should not exceed 5 minutes for the rolled steel plate whose thickness is not more than 80 mm. Thickness of steel plate over 80 mm can be appropriately extended to 10 minutes to ensure that the temperature of steel plate before stacking is controlled above 500 C. The slow cooling time of steel plate with thickness less than 50 mm is 12 hours; the slow cooling time of steel plate with thickness greater than 50 mm is 24 hours. It is strictly forbidden to disassemble and stack in advance.
(二)优化控制冷却
(2) Optimizing Controlled Cooling 方管板坯出现贝氏体一般是由于冷速过快造成的。当冷却速度降低至3-5℃/s时，钢板心部偏析带不再出现贝氏体组织，形成常规的珠光体组织。控制冷却优化后，板坯心部偏析带组织应力明显减少，因组织应力产生的微裂纹得到大大改善。
Bainite in square tube slab is usually caused by too fast cooling rate. When the cooling rate is reduced to 3-5 C/s, the bainite structure is no longer present in the segregation zone of the steel plate core, and the conventional pearlite structure is formed. After controlled cooling optimization, the microstructural stress of segregation zone in the center of slab decreases obviously, and the microcracks caused by microstructural stress are greatly improved.
(三)集中装炉制度
(3) Centralized charging system
在实际生产中轧制钢板的长及宽相差较大，在钢板缓冷时存在堆垛不整齐的情况，导致超宽板边部探伤检验不合格或是超长板头部探伤检验不合格。通过建立集中装炉制度，安排轧制钢板长、宽相近的合同集中装炉，保证后续钢板堆垛的整齐。必要时对方管板坯周边采用石棉布包裹，加强保温效果。
In actual production, the length and width of rolled steel plate are quite different. When the steel plate is slowly cooled, there is irregular stacking, which results in unqualified edge inspection or head inspection of ultra-wide plate. By establishing the centralized charging system, arranging the contract centralized charging of rolling steel plate with similar length and width to ensure the orderliness of subsequent stacking of steel plate. When necessary, asbestos cloth is used to wrap around the square tube slab to enhance the insulation effect.

国内方管价格或继续盘整运行厂家观望操作为…方管方管市场价格继续维稳。昨日夜盘，期货低开，市场信心略受波动，不过今早开市，方管厂家仍以谨慎观望操作为主，国内方管市场价格基本维稳。消息面上：近日河北修订重污染天气应急预案，应急减排将差异化管控；唐山市自今日12时起解除重污染天气Ⅱ级应急响应。由于环保力度没有明显松动，其部分区域仍受影响，目前部分钢企生产… 国内方管市场价格稳中有涨个别地区低价成交…方管方管市场价格稳中有涨。主导市场，北京、广州以稳为主，天津、上海小幅上涨。昨日在期螺飘红的刺激下，市场信心略有恢复，虽然方管市场需求量依旧偏弱，但个别地区低价成交有所好转。今早开盘，期螺再次走高，钢坯也有10元的拉涨，方管市场情绪有所缓和。所以今日开市，方管市场价格稳中有涨。从市场了解到，今日各地成交普遍…