ICS 27.120.20 F65 NB 中华人民共和国能源 行业标准 NB/T 20001—2023 代替 NB/T 20001-2013 压水堆核电厂核岛机械设备制造规范 Fabrication rules for mechanical components of PWR nuclear island 2023 - 05 - 26发布 2023 - 11 - 26实施 国家能源局 发布 NB/T 20001—2023 I 目 次 前言 ................................................................................ IV 引言 ................................................................................ VI 1 范围 .............................................................................. 1 2 规范性引用文件 .................................................................... 1 3 术语和定义 ........................................................................ 2 4 总则 .............................................................................. 3 5 标识与标记 ........................................................................ 3 5.1 一般要求 ...................................................................... 3 5.2 方法 .......................................................................... 3 5.3 位置标记 ...................................................................... 4 5.4 状态标记 ...................................................................... 4 5.5 标识一览表 .................................................................... 4 6 切割和不做焊补的修整 .............................................................. 4 6.1 切割 .......................................................................... 5 6.2 不做焊补的修整 ................................................................ 6 7 成形和公差 ........................................................................ 6 7.1 成形 .......................................................................... 6 7.2 公差 ......................................................................... 10 7.3 弹簧 ......................................................................... 14 8 机械加工 ......................................................................... 18 8.1 一般要求 ..................................................................... 18 8.2 工艺试验或评定 ............................................................... 18 8.3 机加工前准备 ................................................................. 18 8.4 刀具与工件的装夹要求 ......................................................... 18 8.5 机加工要求 ................................................................... 18 8.6 机加工的清洁度管控 ........................................................... 18 8.7 检验 ......................................................................... 18 9 焊接件的装配对正 ................................................................. 18 9.1 一般要求 ..................................................................... 19 9.2 双面焊或从另一侧可接近的单面焊接头装配对正公差 ............................... 19 9.3 内表面不可接近时外侧施焊的焊接接头装配对正公差 ............................... 19 9.4 拼焊封头焊接接头装配对正公差 ................................................. 20 9.5 管子和管道装配对正公差 ....................................................... 20 9.6 超差修整 ..................................................................... 20 NB/T 20001—2023 10 焊接要求 ........................................................................ 20 11 热交换器管子与管板胀接 .......................................................... 20 11.1 一般要求 .................................................................... 21 11.2 胀接 ........................................................................ 22 11.3 检查 ........................................................................ 24 11.4 返工 ........................................................................ 24 12 表面处理 ........................................................................ 24 12.1 镀铬 ........................................................................ 24 12.2 镀锌 ........................................................................ 26 12.3 镀镍 ........................................................................ 28 12.4 电解镀锡 .................................................................... 29 12.5 镀镉处理 .......