焊接应力是焊接部件焊接时产生的应力,焊接过程中产生的内应力及焊件形状和尺寸的变化,焊接过程中的温度场不均匀、局部塑性变形以及由此产生的不同比容的组织是造成焊接应力和变形的根本原因,当焊接温度场未消失时,焊件内的应力和变形称为瞬态焊接应力,温度场消失后的应力和变形称为焊接残余应力,在没有外力的情况下,焊接应力在焊件内部是平衡的,焊接应力和变形在一定条件下会影响焊件的功能和外观,焊接残余应力对结构和部件的影响:

Welding stress refers to the stress generated during welding of welded parts, the internal stress generated during welding and the change of weldment shape and size. The uneven temperature field, local plastic deformation and the resulting organization with different specific volume during welding are the root causes of welding stress and deformation. When the welding temperature field does not disappear, The stress and deformation in the weldment are called transient welding stress, and the stress and deformation after the disappearance of temperature field are called welding residual stress. In the absence of external force, the welding stress is balanced in the weldment. The welding stress and deformation will affect the function and appearance of the weldment under certain conditions. The impact of welding residual stress on the structure and components:

焊接应力一般与什么因素有关(什么是焊接应力)(1)

构件承受荷载之前在横截面上存在的初应力是焊接残余应力,在使用过程中,构件与其他荷载引起的应力发生重叠,产生残余应力的重新分布和二次变形,降低结构刚度和稳定性,在温度和介质的作用下,会影响结构疲劳强度、抵抗应力腐蚀开裂、抗脆性断裂能力和高温蠕变开裂的能力。

The initial stress on the cross section before the member bears the load is the welding residual stress. During use, the member overlaps with the stress caused by other loads, resulting in the redistribution of residual stress and secondary deformation, reducing the structural stiffness and stability. Under the action of temperature and medium, it will affect the structural fatigue strength, resistance to stress corrosion cracking Resistance to brittle fracture and high temperature creep cracking.

焊接应力的消除方法

Elimination method of welding stress

目前采用振动时效、热时效、豪克能PT时效。

At present, vibration aging, thermal aging and houckner Pt aging are adopted.

振动时效

Vibration aging

是常用的消除内部残余内应力的方法,当内部残余应力和振动应力的矢量超过材料屈服强度时,会发生少量的塑性变形,使材料的内应力松弛和减轻。

It is a common method to eliminate the internal residual stress. When the vector of internal residual stress and vibration stress exceeds the yield strength of the material, a small amount of plastic deformation will occur, which will relax and reduce the internal stress of the material.

焊接应力一般与什么因素有关(什么是焊接应力)(2)

热时效

Thermal aging

将工件加热到弹塑性转变温度并保持一定时间,使应力松弛,然后慢慢降温,使工件冷却后处于低应力状态,如果在升温、保温和降温中工艺参数选择不当或没有按照合理的工艺规范操作,应力就无法消除,反而会增加。

Heat the workpiece to the elastic-plastic transition temperature and keep it for a certain time to relax the stress, and then slowly cool down, so that the workpiece is in a low stress state after cooling. If the process parameters are improperly selected or not operated according to reasonable process specifications in heating, insulation and cooling, the stress cannot be eliminated, but will increase.

豪克能时效

Hawk energy aging

是目前彻底消除焊接残余应力并产生出理想应力的方法,疲劳强度可提高50%-120%,疲劳寿命延长5-100倍,耐蚀性提高约400%,处理工艺简单,效果稳定可靠。

At present, it is a method to completely eliminate welding residual stress and produce ideal stress. The fatigue strength can be increased by 50% - 120%, the fatigue life can be prolonged by 5-100 times, the corrosion resistance can be increased by about 400%, the treatment process is simple, and the effect is stable and reliable.

不受工件的材料、形状、结构、厚度、重量和场地的限制,尤其是在施工现场及焊接过程中消除焊接应力更灵活方便,可将焊趾处凹坑、咬边处理成圆滑的几何过渡,降低应力集中系数,去除焊趾处的微裂纹和熔渣,预防形成裂纹。

It is not limited by the material, shape, structure, thickness, weight and site of the workpiece, especially in the construction site and welding process. It is more flexible and convenient to eliminate the welding stress. The pits and undercuts at the weld toe can be treated into a smooth geometric transition, reduce the stress concentration factor, remove the microcracks and slag at the weld toe, and prevent the formation of cracks.

焊接应力一般与什么因素有关(什么是焊接应力)(3)

适用于大型构件的焊缝、焊接修复、焊缝的消除应力处理,环保、节能、安全、无污染,在施工现场使用比较灵活方便。

It is suitable for welding, welding repair and stress relief treatment of large components. It is environmentally friendly, energy-saving, safe and pollution-free. It is flexible and convenient to use on the construction site.

以上为大家详细介绍了关于怎么消除焊接应力的相关内容,希望上述内容对大家有所帮助。

The above introduces in detail the relevant contents on how to eliminate welding stress. I hope the above contents will be helpful to you.

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