1. When pipe is welded, the end head should be blocked to avoid cross-hall wind.
2. Clean the weld after welding, clearly mark the welder's number and date near the weld.
3、环境温度低于 0°、雨雪天气、相对湿度大于 90 或手工焊风速大于 8ms、氩弧焊风速大于 2ms 时除非采取防护措施(如搭防风、防雨棚或室内加热等)否则严禁施焊。
3. Welding is strictly prohibited unless protective measures are taken (such as wind protection, rain shelter or indoor heating) when ambient temperature is lower than 0 degrees, snow weather, relative humidity is greater than 90 or wind speed of manual welding is greater than 8 ms and wind speed of argon arc welding is greater than 2 ms.
4. It is strictly forbidden to start the arc and test current outside the groove and to avoid the scratch of the base metal by the arc.
5. Preheating of Alloy Steel Pipe before Welding
⑴ 12CrMoVG 管道焊接必需停止焊前预热,预热温度范围为 200°~300?
_12CrMoVG pipeline welding must stop preheating before welding. The preheating temperature range is 200 ~300?
(2) Electric heating must be stopped on both sides of groove to avoid partial heating.
⑶ 加热范围为管道对口中心线两侧各不小于三倍壁厚且不小于 50mm 范围加热区域以外 100mm 范围必需采取保温措施以减小温度梯度。
_The heating range is not less than three times the wall thickness on both sides of the central line of the pipeline, and is not less than 50 mm in the heating range beyond 100 mm. Thermal insulation measures must be taken to reduce the temperature gradient.
⑴ 焊接施工时焊工必需严厉依照焊接工艺规程规则的焊接参数停止施焊。焊接过程中要经 常的检测焊缝层间温度必需控制在 200°~300°恒温范围内当温渡过低时 应采取加热措施。
(1) During welding construction, the welder must stop welding strictly according to the welding parameters of the welding procedure rules. In order to detect the interlayer temperature of weld seam frequently in welding process, it is necessary to control the temperature between 200 ~300. When the temperature is too low, heating measures should be taken.
⑵ 管道采用氩弧焊打底焊接。预热温度到达请求后 应立刻停止打底焊接 并应一次性打底 焊终了 且地层焊缝金属厚度不应低于 3mm。
_Pipeline is welded by bottom welding with argon arc welding. After the preheating temperature reaches the request, the bottom welding shall be stopped immediately and the bottom welding shall be finished at one time, and the metal thickness of the formation weld shall not be less than 3 mm.
⑶ 打底焊完毕后应在坚持层间温度的前提下立刻开端填充焊接 依次每道焊缝依次停止。 如 中缀焊接 必需采取保温、缓冷及后热等措施。
_After the bottom welding is finished, the filling welding should be started immediately and stopped in turn for each weld seam on the premise of insisting on the interlayer temperature. For infix welding, measures such as heat preservation, slow cooling and post heat must be taken.
⑷ 重新焊接前必需重新预热。焊接前必需停止检查 确认无裂纹前方可依照原工艺参数继续焊接。
(5) It is necessary to reheat before re-welding. Before welding, it is necessary to stop checking to confirm that no crack can be welded in accordance with the original process parameters.
7. Weld inspection
管道焊缝打底填充、盖面焊接完成停止外表外观检查合格后停留不少于 24 小时后停止 100% 射线检查 请求到达 JB/T4730-2005 的 II 级合格。
After completion of surface inspection, 100% of the requests for radiographic inspection should be stopped after not less than 24 hours to reach the level II qualification of JB/T4730-2005.
8. Weld Repair
(1) Weld repairing must be carried out on the basis of compiling welding repairing process documents.
⑵ 需求返修的焊缝应精确找出缺陷位置返修焊缝时按原焊接工艺停止。补焊工艺与原焊接 工艺相同。焊缝返修和补焊的预热温度应高于原焊接预热温度、预热范围应相应扩展。
(2) Welds requiring repairing should be stopped according to the original welding process when the defect location is found accurately. The repair welding process is the same as the original welding process. The preheating temperature of weld repairing and repairing should be higher than that of original welding and the preheating range should be expanded accordingly.
(3) The number of weld repairs in the same part should not exceed two times, such as two times.
9. Post-weld thermal treatment
(1) The post-weld heat treatment of pipelines should be stopped immediately after the completion of welding.
(2) The electric heating method should be used to control the heating temperature accurately and make the temperature of the weld spread evenly during the heat treatment process.
⑶ 焊缝加热范围为焊缝中心为基准两侧各不小于三倍焊缝宽度且不小于 25mm。加热区以外 的 100mm 范围内也必需停止保温。
(3) The heating range of the weld is not less than three times the width of the weld and not less than 25 mm on both sides of the base line. The insulation must also be stopped within the range of 100 mm outside the heating zone.
⑷ 热处置参数 加热温度为 720°---750℃恒温 1 小时 升温速度为 400℃以上 134℃/h 冷却速度为 165℃/h，400℃以下空气中自缓冷。
_The heating temperature of heat treatment parameters is 720 750 and the heating rate is above 400 and 134 per hour. The cooling rate is 165 per hour. The air below 400 is self-cooling.
_When the temperature is constant, the difference between the upper and lower temperatures should be controlled less than 65 C.
_Temperature control should be precise in the process of thermal disposal, and the constant temperature deviation should not exceed (+25 C) and not exceed the temperature range of thermal disposal.
⑺ 热处置温度检测可运用热电偶检测并应运用自动记载仪记载热处置曲线在加热区域内 测点不应少于 2 点。 ⑻ 热处置完毕后应对焊缝停止硬度检测。每道焊缝不少于 3 点 分别散布在焊缝、热影响区和母材。检测结果焊缝硬度应不超越母材硬度值 100HB 如不合格应重新热处置。
_Thermocouple can be used to detect the temperature of thermal disposal and automatic recorder should be used to record the heat disposal curve at no less than 2 points in the heating area. _Hardness testing should be stopped after heat treatment. No less than 3 points of each weld are scattered in the weld, heat affected zone and base metal respectively. The test results show that the weld hardness should not exceed the hardness value of base metal 100HB. If it is not qualified, it should be re-heated.
This article is from: Jinan galvanized pipe more content please click: http://www.jnxxjm.com, we will provide you with a satisfactory service to ask questions, welcome your call!