一、材料性能 高温炼油设备往往采用铁素体低合金钢。对于压力容器和管道,各设计规范均以材料经充分热处理后达到的抗拉性能为基础,来规定材料的许用应力值。但是,经各制造工序后,各种供货状态都已改变。如在上临界点以上热成形则组织会重新转变,成形温度和冷却速度绝不会与材料最初的热处理条件相同。冷成形会产生残余应力,提高材料硬度并降低断裂韧性。而焊接会使接头各部分 First, the material properties High temperature refining equipment often use ferritic low alloy steel. For pressure vessels and piping, each design specification specifies the allowable stress value of the material based on the tensile properties achieved after the material has been sufficiently heat treated. However, after the various manufacturing processes, the status of various supplies has been changed. If thermoforming occurs above the upper critical point, the texture will change again, and the forming temperature and cooling rate will never be the same as the initial heat treatment of the material. Cold forming will produce residual stress, improve material hardness and reduce fracture toughness. Welding will make the various parts of the joint