Optimization of PWHT on Dissimilar Friction Welding for Piping Material of A105 to A312

Abstract

A study on dissimilar friction welded joints were performed using 22 mm diameter tube-to-bar in forging bar steel(ASTM A105) to stainless pipe steel(ASTM A312) for piping materials. The main friction welding parameters were selected to endure good quality welds on the basis of visual examination, tensile tests, Virkers hardness surveys of the bond of area and HAZ, and macrostructure investigations. The specimens were tested as-welded and post-weld heat treated(PWHT). The tensile strength of the friction welded joints was increased up to 100 ％ of the A105 base metal under the condition of heating time(HT). Optimal welding conditions were n=2,000 rpm, HP=50 MPa, UP=100 MPa, HT=5 sec and UT=10 sec when the total metal loss(Mo) is 11 mm. The peak of hardness distribution of the friction welded joints can be eliminated by PWHT. Two different kinds of materials are strongly mixed to show a well-combined structure of macroparticles without any molten material and particle growth or any defects. In addition, the results of the radiological examination(RT) showed that there was no blowhole in the friction welding area.

Evaluation of the mechanical properties of Inconel 718 to SCM 440 dissimilar friction welding through real-time monitoring of the acoustic emission system

“…Materials with less strength and hardness tend to plastically deform under the dynamic force and high temperature during friction welding. 27–31 Figures 8(b) and 6(c) indicate the microstructures of the weld flash which is formed during welding on the IN718 side and on the SCM440 side, respectively. As can be seen from the macrostructures, the weld flash on the IN718 side is not noticeable compared to the SCM440 side.…”

Microstructure and Mechanical Properties of Solid-State Rotary Friction Welded Inconel 713C and 32CrMo4 Steel Joints Used in a Turbocharger Rotor

“…As a result, Inconel 713C superalloys showed no distortion. Materials with less strength in dissimilar friction stir welding tend to plastically deform under high temperatures and dynamic force [ 44 , 51 , 52 ]. The structure of the γ-phase of the nickel-based superalloy is an austenitic body-centred cubic lattice that contains a large number of elements, such as Cr, Mo, W, and Co.…”