Hot Cracking Resistance Research Articles

A method of calculating the hot cracking resistance of welded joints

A method of calculating the hot cracking resistance of welded joints

Hot cracking resistance of welded joints in austenitic steels produced by high-speed laser welding

(1997). Hot cracking resistance of welded joints in austenitic steels produced by high-speed laser welding. Welding International: Vol. 11, No. 2, pp. 149-151.

Increasing hot cracking resistance and fatigue strength of laser welded joints in creep-resisting alloys

Increasing hot cracking resistance and fatigue strength of laser welded joints in creep-resisting alloys

Hot cracking resistance and distribution of elements in welded joints with metal with a varying cyclic composition

Hot cracking resistance and distribution of elements in welded joints with metal with a varying cyclic composition

薄鋳片-簡略熱延プロセスにおける軟質冷延鋼板の析出制御

Although thin slab-direct hot rolling process is expected as a future process of steel sheet production, its metallurgy has not been investigated thoroughly. In this paper, the metallurgy of mild steel in thin slab-direct hot rolling process has been discussed with special attention to the precipitation behavior of MnS and its influence on the hot-cracking at the edge of hot bands and the mechanical properties of cold rolled low carbon steel sheets. The following results are obtained :1. The hot-cracking resistance and mechanical properties of cold rolled sheets produced through thin slab-direct hot rolling process are not inferior to those produced through a conventional process, if S content is reduced and/or proper heat treatment prior hot rolling is carried out.2. The experimental findings indicate that MnS precipitates under a condition of the local equilibrium at the MnS/γ interface.3. The hot-cracking is probably caused by the remelting reaction of austenite at grain boundaries occupied by sulfur. For explaining the experimental findings, not only the equilibrium but also the kinetics of the diffusional reaction must be considered for the remelting process.

A calculation and experimental method of determining the hot cracking resistance of weld metal

A calculation and experimental method of determining the hot cracking resistance of weld metal

耐海水６％Ｍｏステンレス鋼の溶接性

Corrosion resistant alloy welds for seawater applications are necessary to be over-alloyed with Cr, Mo and nitrogen to have an increased Pitting Index value. The desired weld chemistry also requires less microsegregation of Cr and Mo and precipitation free microstruciure not only for higher corrosion resistance but also for good mechanical properties and weld hot-cracking resistance. Based on such requisites for the welds, nitrogen-added Ni-based filler metal, 22Cr-60Ni-9Mo-0.1N, was developed for the welding of a 6%Mo superaustenitic stainless steel.The weldment by the newly developed filler metal showed excellent chloride corrosion resistance comparable to the base metal. The weld solidification and microstructure were fully austenitic without any other phases and brittle precipitates in the whole weld. Thereby, the weldment also offered good ductility, toughness and hot-cracking resistance superior to the weldment by the conventional Alloy 625 filler metal.

Effect of grain size on hot cracking resistance of the HAZ metal of welded joints in creep-resisting alloys

Effect of grain size on hot cracking resistance of the HAZ metal of welded joints in creep-resisting alloys

Addition of yttrium to weld metal for increasing the hot cracking resistance in welding a stable austenitic steel

Addition of yttrium to weld metal for increasing the hot cracking resistance in welding a stable austenitic steel

Study of improving the hot-cracking susceptibility of the nickel-iron electrode for welding cast iron

The nickel-iron electrode for welding cast iron is susceptible to hot cracking. In order to improve its hot-cracking susceptibility, the effects of rare earth (RE), C, Si, Cu, Mn, S, and P on its hot cracking were investigated. The hot-cracking test machine based on the theory of critical deformation speed was applied. The optimum RE, C and Si contents of the weld metal were determined. Variation in their contents greater or less than the optimum value resulted in reducing the hot-cracking resistance. Mn, Cu, S, and P increase the hotcracking susceptibility of the weld metal. The reasons for these phenomena were discussed. The comprehensive utilization of RE, C and Si can remarkably improve the hot-cracking susceptibility of the nickel-iron electrode for welding cast iron.

Hot cracking resistance of titanium alloys in welding

Hot cracking resistance of titanium alloys in welding

Metallurgical factors influencing the hot cracking susceptibility of nickel-iron type cast iron welding rods

Abstract Nickel-iron cast iron welding rods are comparatively susceptible to hot cracking. Using the HRL-1 Type hot cracking tester and the critical deformation velocity method, the influence of rare earth yttrium and of carbon, cobalt, silicon, copper, manganese, sulphur and phosphorus on hot cracking has been studied to improve the hot cracking resistance properties of nickel-iron welding rods. Experiments showed that there was an optimum value for the content of rare earth yttrium and of carbon, cobalt and silicon in weld metal, and that to deviate from this value led in each case to a deterioration in hot cracking resistance properties: manganese, copper, sulphur and phosphorus all increased weld metal hot cracking susceptibility. It is concluded that use of the rare earth yttrium and of cobalt and carbon markedly improves the hot cracking resistance properties of nickel-iron type cast iron welding rods.

Solidification and solidification cracking in nitrogen-strengthened austenitic stainless steels

The solidification behavior of three heats of nitrogen-strengthened austenitic stainless steel was examined and was correlated with solidification mode predictions and with hot cracking resistance. The heat of NITRONIC* 50 solidified by the austenitic-ferrite mode, and the NITRONIC 50W and NITRONIC 50W - Nb heats solidified by the ferritic-austenitic mode. This behavior was in good agreement with predictions based on Espy’s formulas for Cr and Ni equivalents. Both the NITRONIC 50W and NITRONIC 50W + Nb welds contained primary delta-ferrite, with the latter weld and the NITRONIC 50 weld also containing some eutectic ferrite. Solute profiles in austenite near the eutectic ferrite showed decreasing Fe and increasing Cr, Ni, Mn, and Mo relative to austenite in the dendrite cores. Numerous Nb-rich precipitates were found on the eutectic ferrite/austenite interfaces and within the eutectic ferrite. The precipitates were mainly Nb(C, N), with some Z-phase, a Nb-rich nitride, also detected. One instance of the transformation of eutectic ferrite to sigma-phase was observed to have occurred during cooling of the NITRONIC 50 weld. Hot cracking was seen in the NITRONIC 50 and NITRONIC 50W + Nb welds and resulted from the formation of a niobium carbonitride eutectic in the interdendritic regions. In the absence of Nb, the NITRONIC 50W heat formed no observable eutectic constituents and did not hot crack. The presence of hot cracks in the NITRONIC 50W + Nb weld indicates that solidification by the ferritic-austenitic mode did not counteract the effects of small Nb additions.

Effect of molybdenum and tungsten on the hot cracking resistance of weld metal in welding 06KhN28MDT steel

Effect of molybdenum and tungsten on the hot cracking resistance of weld metal in welding 06KhN28MDT steel

Ｎｂ含有オーステナイトステンレス鋼の溶接高温割れ感受性

Hot cracking of Nb-containing austenitic stainless steel was studied.The following results were obtained;1) Hot cracking susceptibility of Nb-containing material increases detrimentally in both fully γ-phase and (γ+a)-phase weld metal when Nb content exceeds about 0.40%2) C improves hot cracking resistance in case of high Nb content (0.78 %), but indicates hardly noticeable effect when the Nb content is low (0.26 %).The effect of N on hot cracking is not so significant within the range of 0.015 % to 0.12 %.3) Increase of hot cracking susceptibility is due to the segregation of Nb, C and N at grain boundaries, which was found on the crack fracture surfaces in the welds by Auger Electron Spectroscopy.Based on these results, 40 mm thick plate of modified low-C, type 347 stainless steel was made and welded by GTAW, SMAW and SAW. Microcrack resistance of these welds proved to be quite satisfactory.

ALUMINUM F214

Abstract ALUMINUM F214 is an aluminum-magnesium-silicon sand casting alloy having good resistance to hot cracking and fair resistance to pressure tightness. It is recommended for ornamental hardware and architectural castings requiring anodizing. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on corrosion resistance as well as casting, heat treating, and machining. Filing Code: Al-183. Producer or source: Aluminum Company of America.

SILAFONT-7

Abstract Silafont-7 is an aluminum piston alloy for sand, permanent mold and die castings. It has high strength, particularly good hot-crack resistance and limited corrosion resistance. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance as well as casting, heat treating, machining, and joining. Filing Code: Al-150. Producer or source: Swiss Aluminium Ltd.