有時方管坯會出現分層問題，從而導致探傷（shāng）不合（hé）。要預防這（zhè）一缺陷（xiàn），我們（men）可以采取以下三（sān）點（diǎn）處理措（cuò）施（shī）：(一（yī）)優化緩冷時間：優化方管板坯的緩冷工藝，主要針對堆（duī）垛溫度和堆垛持續時間。軋（zhá）製鋼板厚度不大於80mm鋼板熱矯直後，在（zài）冷（lěng）床停留時間不得超過5min。厚度大（dà）於80mm鋼板可適當延長至10min，確（què）保鋼板成垛前溫度控製在500℃以上。鋼板厚度不大（dà）於50mm鋼板（bǎn）緩冷時間在12h;厚度大於50mm的鋼板緩冷時間24h，嚴禁提前拆（chāi）垛（duǒ）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)優化控製（zhì）冷卻（què）
(2) Optimizing Controlled Cooling 方管板坯出現貝氏體（tǐ）一般是由於冷（lěng）速過快造成的。當冷卻（què）速度降低（dī）至3-5℃/s時，鋼板心部偏析帶不（bú）再出現貝氏體組織，形成常規的珠光體（tǐ）組織。控製冷卻優化後，板坯心部偏析帶組織應力（lì）明（míng）顯減（jiǎn）少，因組織（zhī）應力產生的（de）微裂紋得到（dào）大大（dà）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)集中裝爐製度
(3) Centralized charging system
在實際生產（chǎn）中軋製鋼板的長（zhǎng）及寬相差較大，在鋼板緩冷時存（cún）在堆垛不整齊的情況，導致超（chāo）寬板邊部（bù）探傷檢驗不合格或是超長板頭部探傷檢（jiǎn）驗不合格。通過（guò）建立集中裝爐製度，安排軋製鋼板（bǎn）長、寬相近的合同集中裝爐，保證後續鋼板堆垛的整齊。必要時（shí）對方管板（bǎn）坯（pī）周邊（biān）采用石棉（mián）布（bù）包裹，加強保（bǎo）溫效果。
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.
