Stainless steel elbow to normalizing and tempering heat treatment, machining port, wall thickness is required to wear and machining allowance. The general allowance is 10% to 20% of the wall thickness of the elbow. The smaller the D ratio of the wall thickness and the section diameter, the better the fitting performance of the die, but the more easily the inner arc of the bend is lost.
According to the metal in the plastic deformation of constant volume, push in the form of constant wall thickness (actually slightly thin), elbow arc length and equal to the length of the billet, derived push system tube diameter formula: if the actual choice of the tube diameter than the calculated according to the formula, the DP value, mold and joint performance is good, but in the elbow of the arc easily wrinkling. If the actual selection of tube blank outside diameter ratio is calculated by the formula of Dp value, the result is just the opposite.
The principle of determining the stainless steel elbow heating temperature is above material austenitizing temperature, and push the system elbow inside the main compressive stress is less than the yield limit under the temperature of materials. Material austenitizing temperature is higher, the higher the heating temperature. The higher the material yield limit of high temperature, the higher the heating temperature.
Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)