To reduce welding residual stress (WRS) of a class 3 pressure vessel during the reconstruction, temper bead welding technique (TBWT) was applied to the container. To compare WRS causing by common welding and TBWT, WRS of the two different kinds of welded specimens of 16Mn steel were measured and evaluated by X-ray method. To study the effect of butt weld reinforcement height on WRS, welds with and without weld reinforcement were measured. The results show that longitudinal stress was reduced obviously and the lateral stress is the maximum principal stress for TBWT; WRS of TBWT T-shape specimens were obviously decreased which proves TBWT is better than common welding procedure; WRS was decreased by more than 25% after removing the weld reinforcement and further proves that it is one of effective ways to reduce WRS in engineering application.

Tests including the constant load tensile, three point bending and hydrogen induced cracking (HIC) are executed to evaluate the comprehensive properties of the 15CrMoR(H) with new smelting process in saturated hydrogen sulfide (H2S) according to NACE and National Standard. By analyzing and fitting the results of constant load tensile test, the stress-life mathematical model of this material is given. Results show that the stress corrosion threshold of the constant load tensile is 0.7Rel (252MPa).The nominal stress of three point bending SC is higher than 4.5 Rel (1620MPa). Results of HIC test show that the crack length rate CLR is 4.40%, the crack thickness rate CTR is 0.87% and the crack sensitive rate CSR is 0.04%. According to EFC standard, the safety margin is 3.4, 3.4 and 37.5 times respectively. All the experimental results show that the 15CrMoR(H) material has excellent H2S stress corrosion cracking resistance properties.

Based on the importance and complex working environment of hydraulic support, welding residual stress (WRS) measurement to main components were carried out respectively by X-ray diffraction and the measured data were further analyzed theoretically. Tests were made on the gob shield and base for two times, each was measured before and after heat treatment respectively. The results indicate that WRS in the base are higher than that in the gob shield before heat treatment. After heat treatment, residual stress (RS) level of gob shield and base decreased significantly, WRS in every region keep at a lower level and regional RS differences become smaller. Therefore, heat treatment processes is an effective method to reduce RS of hydraulic support after welding. Through the test results we measured, got the real residual stress level of gob shield and base, which can provide the basis of experiment to search for an appropriate welding and heat treatment process.

In order to study the residual stress of Al2O3 ceramics and kovar alloy after brazing, this article conducted both X-ray diffraction and strain gauges measurement. Using Stress diffractometer and constant strength beam calibration method to examine the x-ray diffraction characteristics of these two materials. And compare measured results and theoretical results. It is shows that the Al2O3 ceramics has two obvious diffraction peaks in 140°~170°, where the diffraction peak at 2θ=153° can reflect the changes of stress more accurately then one at 2θ=146°. For kovar alloy, there is only one diffraction peak at 2θ=149° in range of 140°~170° and it has good linear relationship with stress.

In this paper, theoretical and experimental researches were done to find the repeated cracking reason of stuffing box in a super hyper pressure compressor. The mathematical expression of the assembly pressure was deduced in interference fit. From macro and micro perspectives, residual stresses were measured by X-ray diffraction in typical position of stuffing box when the packing box in combination and separation states. Besides, metallography and fracture examinations were carried out. The results showed that the real magnitude of shrink range of the failed stuffing box was only account for 12% of the designed size requirements, however, under this working condition this stress was not sufficient to cause cracking; Unqualified smelting process and tensile stress concentration in tank caused micro crack, which finally results in fracture of the stuffing box under fatigue mode.