In this work, a weld metal in K65 pipeline steel pipe has been processed through self-designed post-weld heat treatments including reheating and tempering associated with hot bending. The microstructures and the corresponding toughness and microhardness of the weld metal subjected to the post-weld heat treatments have been investigated. Results show that with the increase in reheating temperatu...

This study investigated the microstructures of pearlite and martensite transformed from ultrafine-grained austenite in 0.45C steel and Vadded 0.45C steel. The mean prior austenite grain sizes were refined to be 4.5 μm in the 0.45C specimen and 2.4 μm in the V-added 0.45C specimen through cyclic heat treatment of austenitizing and water quenching, i.e., repetition of martensite § austenite trans...

The effect of cooling rate-induced microstructural changes on corrosion resistance in a CO2-saturated 3.5 wt% NaCl solution have been explored for the API L80–1Cr steel. corroded layer majorly contains siderite, akagenite, and undissolved cementite. amount FeCO3 this is larger water-cooled sample with martensitic structure, whereas furnace-cooled ferritic-pearlitic structure akagenite. retained...

In this study, six flexible pipe steel armor wires used in oil and gas transportation are characterized, their hydrogen diffusion coefficients uptakes measured using an electrochemical permeation technique. The have ferritic–pearlitic microstructures with round, lamellar, or partially lamellar carbides the shape orientation of grains indicate that were plastically deformed to different degrees....

Comprehensive studies have been carried out and the main regularities of cementite decomposition during thermocyclic processing carbon-based hypereutectoid steels established.

In order to research the evolution of microstructures and properties SCM435 wire rod after annealing with different initial structures, two kinds microstructure (B+M F+P) rods were used simulate spheroidizing annealing, softening stress relief processes respectively. The results show that under same process conditions, spheroidization grade B+M was 1-2 higher than F+P, while hardness does not d...

The demands for increasing the efficiency and lowering the environmental effects in iron and steelmaking industries have given rise to interests in application of direct reduction (DR) processes for production of iron by different gases. These advancements require comprehensive models for better control of the process conditions and the product properties. In the present thesis fundamental aspe...

To gain a deeper understanding of the dynamic accommodation mechanism internal stress in pearlite originating from lattice misfit between ferrite and cementite phases, parameter ratios cementite, bθ/aθ cθ/aθ, were locally analyzed detail using electron backscatter diffraction (EBSD) technique. The EBSD analysis revealed that lamellae clearly differed those spheroidized particles, indicating has...