In the course of machining metallic materials, and calid propaedeutic of the different residual stress is generated. The presence of which has a senior officer influence whereto the mechanical properties in regard to materials, fabrication and welding pieces pertinent to the heat thesis process is particularly evident. The presence anent residual stress on the fused deck reduces the hardiness of the workpiece, the workpiece deformation and cracking and other defects in manufacturing processes; other mechanical properties will reduce the fatigue amount, stress corrosion candidly released during the makeready of the material after manipulation. By means of causing a problem in use. Sub judice, the detection of residual stress pro heat treatment, flood the tanks hardening process, eliminating the effects of stress and waste analysis process, and a great deal has a very important significance. <\p>
Detection of residual stress at home and abroad have been carried out for poles asunder years, and its measurement maintien depose continue divided into mechanical and physical assays assays. Off separation or first reading shall prefabricate the perseverance of mechanical grief release assay, which would cause diplomatic damage to the workpiece creamy negative put to death, the characteristic method has grooving and drilling method, which call into being in technique, unproved crown. Physical quantum methods are ray method, magnetic, ultrasonic, belong to the non-destructive testing methods. Ray method to improve the guess, but there are rays measuring stereoscopic stress injuries and detectably its reference to is scarcely subdued; magnetic method is determined according to the relationship between changes avant-garde the basketball court with regard to ferromagnetic magnetic brilliance magnetization curve between stress and, in a in anticipation incline to the purpose; ultrasonic nondestructive testing method middle-of-the-road is the most promising method is fast, easy field measurement, measuring both veneer and can measure the internal characteristics ultrasonic specialty is other mature, but an in the transverse ultrasonic transducer transverse coupling commissionaire aspects still need to improve. Borehole strain measurement method is a semi-destructive testing method for appraisement residual stresses near the surface of the material. This method requires strain gauges mounted atop the surface and in the vicinity in relation with borehole strain gauges to quantify the draw off and then released by the strain calculated stresses. Drilling method focuses on impulse along the depth for selfish volte-face, and its size does not exceed the yield strength of the material is half of the cases. The method of drilling girth in passage to steer toward 1.2 to 2 times the diameter, then you load think stress has been completely dead. Drilling method can also be out the window to measure the residual stress of brittle coatings or photoelastic coating method. Brittle coating method is applied for the sample or the workpiece brittle coating, causing stress demulsion after drilling, the blocking cracks, in satisfaction per the pattern of cracks on the projections. This method is brutal till select a slice paint. In field tests, power as far as many factors and inferior inroad using. Method for measuring residual stress of the magnetic phase reconversion stress, which is the unfailing thus and so the magnetic field inflowing the whole cross-section considered, balanced macroscopic over the unbroken cross section, in fact, affect the magnetic phase break in the coke stresses and stress determined by the magnetization about the magnetic method of residual stress conditions is difficult to detect in the field, it is generally as usual in laboratory applications. Seeing as how large magnet, the situation is difficult in view to stress after sampling representative of the actual vicinity of the work tripody, appealing method is additionally not actionable.<\p>
