金属波纹管的性能主要取决于制造波纹管的材料的质量

制作波纹管所用材料的质量主要取决于金属波纹管的性能

金属波纹管的性能参数

1） 最大压缩长度

金属波纹管在外力的作用下，当波纹管彼此紧密接触时，金属波纹管被压缩到一定长度。

2） 最大压缩位移

当金属波纹管被压缩到波纹管之间的紧密接触时所能产生的最大位移。当波纹管达到最大压缩位移时，往往会发生塑性变形，因此在运行中不允许达到此值。

3） 容许位移和工作位移

金属波纹管在不发生塑性变形的情况下所能达到的最大位移称为允许位移，工作过程中的最大位移称为工作位移。为保证波纹管在整个工作过程中性能稳定可靠，使用寿命高，工作位移一般为允许位移的40%～50%。

4） 耐压和工作压力

波纹管在保持稳定状态或不发生塑性变形（如不破坏波距均匀性、波纹不偏转等）的条件下所能承受的最大静压称为波纹管的耐压。工作压力是指整个工作过程中的最大作用力。为保证波纹管性能稳定可靠，使用寿命高，工作压力一般为耐压的40%～50%。

5） 破裂压力

引起波纹管壁破裂的临界压力称为破裂压力，它代表波纹管的最大抗压强度。在工作过程中，波纹管的工作压力远小于此压力。

6） 刚度和灵敏度

刚度是金属波纹管单位位移所需的力或压力，而灵敏度是刚度的倒数，即作用在波纹管上的单位力或压力所产生的位移。由于波纹管能承受集中力、压力和弯矩，其刚度按荷载类型可分为集中力刚度、压力刚度和弯曲刚度。其中，集中力刚度是最常用的，这被称为波纹管刚度。

7） 有效面积

它代表了金属波纹管将压力转化为集中力的能力。有效面积是一个等效面积，压力将在该面积上产生相等的轴向力。

8） 稳定性

金属波纹管在外力作用下抵抗局部失稳或整体失稳的能力。

9） 气密性

指金属波纹管在一定内外压差下保证不泄漏的性能。风箱必须密封。

10） 寿命

金属波纹管的使用寿命用波纹管的载荷变化次数表示，直至泄漏未被密封为止。生命是一个多元函数。它与波纹管的工作位移、工作压力、工作介质、温度范围、刚度、频率、工艺因素、安装和材料特性有关。

11） 零偏移量

以自由长度为零位，在集中荷载作用下，将波纹管压缩至一定位移值，保持1分钟，然后解除荷载。此时，将波纹管的长度与自由长度进行比较，其差称为零位偏移。它与材料的性质和位移有关。

12） 弹性性质

金属波纹管的变形与其载荷之间的关系称为弹性性质。弹性性质可以是线性的，也可以是非线性的。波纹管弹性特性的非线性依赖于其几何形状和位移。线性偏差用非线性值表示，非线性值是指实际弹性特性曲线与直线的最大偏差与波纹管最大变形的比值。

13） 滞后

金属波纹管在加载和卸载条件下绘制弹性特性曲线时会出现迟滞现象。弹性滞回值由相同荷载下测得的最大加卸载位移差与最大位移之比确定。

14） 弹性后效

金属波纹管的弹性后效是波纹管的位移滞后于载荷。例如，由于弹性后效现象，卸载后仪器指针不能立即归零。

三。金属波纹管材质

金属波纹管的性能主要取决于制造波纹管所用材料的质量和波纹管的几何参数

The performance of metal bellows mainly depends on the quality of the material used to make bellows

Performance parameters of metal bellows

1) Maximum compression length

Under the action of external force, the metal bellows are compressed to the length when the corrugations are in close contact with each other.

2) Maximum compression displacement

The maximum displacement that can be produced when the metal bellows are compressed to the close contact between the corrugations. When the bellows reaches the maximum compression displacement, plastic deformation often occurs, so it is not allowed to reach this value in operation.

3) Allowable displacement and working displacement

The maximum displacement that metal bellows can achieve without plastic deformation is called allowable displacement, and the maximum displacement in the working process is called working displacement. In order to ensure the stable and reliable performance and high service life of bellows in the whole working process, the working displacement is generally 40% ~ 50% of the allowable displacement.

4) Resistance to pressure and working pressure

The maximum static pressure that the bellows can bear under the condition of maintaining a stable state or no plastic deformation (such as no damage to the uniformity of wave distance, no deflection of ripple, etc.) is called the pressure resistance of the bellows. The working pressure refers to the maximum force in the whole working process. In order to ensure the stable and reliable performance and high service life of the bellows, the working pressure is generally 40% ~ 50% of the pressure resistance.

5) Rupture pressure

The critical pressure that causes the rupture of the wall of the bellows is called the rupture pressure, which represents the maximum compressive strength of the bellows. In the working process, the working pressure of bellows is far less than this pressure.

6) Stiffness and sensitivity

Stiffness is the force or pressure required by the unit displacement of metal bellows, while sensitivity is the reciprocal of stiffness, that is, the displacement generated by the unit force or pressure acting on the bellows. Because bellows can bear concentrated force, pressure and bending moment, its stiffness can be divided into concentrated force stiffness, pressure stiffness and bending stiffness according to the type of load. Among them, the concentrated force stiffness is the most commonly used, which is referred to as the bellows stiffness.

7) Effective area

It represents the ability of metal bellows to convert pressure into concentrated force. The effective area is an equivalent area, and the pressure will produce equal axial force on this area.

8) Stability

The ability of metal bellows to resist local instability or overall instability under external force.

9) Airtightness

It refers to the performance of metal bellows to ensure no leakage under a certain internal and external pressure difference. The bellows must be sealed.

10) Life span

The service life of metal bellows is expressed by the number of load changes of bellows until the leakage is not sealed. Life is a multivariate function. It is related to the working displacement, working pressure, working medium, temperature range, stiffness, frequency, technological factors, installation and material characteristics of bellows.

11) Zero offset

Take the free length as the zero position, under the action of concentrated load, compress the bellows to a certain displacement value, keep it for one minute, and then remove the load. At this time, compare the length of bellows with the free length, and the difference is called zero position offset. It is related to the properties of the material and the displacement.

12) Elastic properties

The relationship between the deformation of a metal bellows and its load is called elastic property. The elastic properties can be linear or nonlinear. The nonlinearity of elastic properties of bellows depends on its geometry and displacement. The linear deviation is expressed by the value of nonlinearity, which refers to the ratio of the maximum deviation of the actual elastic characteristic curve to the straight line and the maximum deformation of the bellows.

13) Lag

The hysteresis of metal bellows occurs when the elastic characteristic curve is drawn under the condition of loading and unloading. The elastic hysteresis value is determined by the ratio of the maximum displacement difference between loading and unloading measured under the same load and the maximum displacement.

14) Elastic aftereffect

The elastic aftereffect of metal bellows is that the displacement of bellows is later than the load. For example, due to the phenomenon of elastic aftereffect, the pointer of the instrument cannot return to zero immediately after unloading.

3. Material of metal bellows

The performance of metal bellows mainly depends on the quality of the material used to make the bellows and the geometric parameters of the bellows after forming. Whether the performance of bellows can meet the design requirements largely depends on the manufacturing quality of these materials. Distortion of material, uneven welding, irregular waveform and residual damage after forming can cause high stress in local parts, resulting in premature failure of bellows. The selection of bellows materials should mainly consider the following points:

金属波纹管的性能主要取决于制造波纹管的材料的质量

金属波纹管的性能参数

1）最大压缩长度

在外力作用下，金属波纹管被压缩到波纹之间彼此互相紧密接触时的长度。

2）最大压缩位移

金属波纹管压缩到波纹之间相互紧密接触时所能产生的最大位移。当波纹管达到最大压缩位移时，往往已产生了塑性变形，所以工作时不允许达到这一数值。

3）允许位移和工作位移

金属波纹管不产生塑性变形情况下所能达到的最大位移称允许位移，而工作过程的最大位移你工作位移。为了保证波纹管在整个工作过程中性能稳定可靠和较高的使用寿命，工作位移般取允许位移的40%~50%。

4）耐压力和工作压力

波纹管在保持稳定状态或不产生塑性变形（如波距均匀性不破坏，波纹不歪斜等）条件下，能承受的最大静压力称波纹管的耐压力。而工作压力指在整个工作过程中，承受的最大玉力为了保证波纹管工作时性能稳定可靠和具有较高的使用寿命，工作压力一般取耐压力的40%~50%。

5）破裂压力

引起波纹管管壁破裂损坏时的临界压力称破裂压力，它表征了波纹管的最大耐压强度。在工作过程中，波纹管的工作压力远小于此压力。

6）刚度与灵敏度

刚度就是金属波纹管产生单位位移所需要的力或压力，而灵敏度则是刚度的倒数，即作用于波纹管上单位力或压力所产生的位移。由于波纹管能承受集中力、压力和弯矩，所以它的刚度根据承受载荷的类别可分为集中力刚度、压力刚度和弯曲刚度。其中以集中力刚度最为常用，把它简称为波纹管的刚度。

7）有效面积

它表征金属波纹管将压力转换为集中力的能力，有效面积是一个等效的面积，压力作用在这个面积上将产生相等的轴向力。

8）稳定性

金属波纹管在外力作用下，抵抗引起局部失稳或总体失稳的能力。

9）密封性

指金属波纹管在一定的内、外压差作用下保证不泄漏的性能，波纹管必须具有密封性。

10）寿命

金属波纹管的寿命，用波纹管直至不密封泄漏时为止的负荷变化次数表示。寿命是一个多元函数．它和波纹管的工作位移、工作压力、工作介质、温度范围、刚度、频率、工艺因素、安装情况和材料特性等有关。

11）零位偏移

以自由长度为零位，在集中载荷作用下，将波纹管压缩到某一位移值，保持一分钟后，卸除载荷，这时以波纹管长度与自由长度作比较，其差值称零位偏移。它与材料的性质以及位移量的大小有关。

12）弹性特性

金属波纹管某一点的变形与其负荷之间的关系称弹性特性。弹性特性可以是线性的，也可以是非线性的。波纹管弹性特性的非线性取决于它的几何形状和位移量。线性偏差用非线性度值来表示，非线性度值是指实际的弹性特性曲线对直线的最大偏差与波纹管的最大变形之比。

13）滞后

金属波纹管的滞后，是在加载及卸载的倩况下绘制弹性特性曲线时出现的，弹性滞后值是由相同负荷作用下所测得的加载与卸载的最大位移差与最大位移之比来确定。

14）弹性后效

金属波纹管的弹性后效表现为波纹管的位移比所加的负荷来得迟。例如，由于弹性后效的现象，仪表的指针在卸除负荷后不能立即回到零点。

3．金属波纹管的材料

金属波纹管的性能主要取决于制造波纹管的材料的质量和波纹管成形后的几何参数．波纹管的性能能否满足设计要求，很大程度上取决于这些材料的制造质量。材料的畸变，焊接不均匀，成形后波形不规则和残余损伤等都能引起局部部位的高应力，从而导致波纹管过早的破坏。波纹管材料的选择主要应考虑如下几点：