Weld Filler Research Articles

Short-range order effects on the tensile behavior of a nickel-base alloy

A nickel base weld filler metal alloy with nominal composition of 67 pct Ni, 20 pct Cr, 3 pct Mn, 3 pct Fe, and 2.5 pct Nb (Cb) is used to make austenitic-ferritic dissimilar metal joints. Tensile properties were determined for this alloy over the range 25 to 732°C at strain-rates of 3×10−6 and 3×10−4/s. Above about 450°C, both the yield strength and the ultimate tensile strength in the low strain-rate tests showed significant increases over the strengths at the higher strain-rate. The enhanced values for the yield strength persisted to the highest test temperature (732°C), whereas the ultimate tensile strength for the low strain-rate fell below the curve for the higher strain-rate at about 600°C. Above 600°C, the ultimate tensile strength dropped off rapidly and at 677°C approached the yield strength (i.e., the uniform elongation dropped to less than 1 pct). The strain-rate effects have been attributed to “K-state” formation, an effect that investigators have attributed to short range order in other Ni−Cr base alloys.

Metallographic analysis of a steel plate which failed in service in a coal gasifier

A material sample containing a portion of the crack that caused failure of the inner shell of a coal gasifier was examined metallographically and compared with a sample of the same material far from the region of failure. Corrosion pitting was observed on the base metal but seemed to have had no catastrophic effect. However, limited observations indicated that corrosion pitting of weld filler metal produced the failure.

Radiation and Temper Embrittlement Processes in Advanced Reactor Weld Metals

Experimental weld filler metals having high resistance to radiation embrittlement at ≃550 F (288 C) have been developed for quenched and tempered A543 and A542 steel. The filler metals are from a special 2-1/4 Cr-1 Mo-0.40Si-0.10C composition series formulated to study the effects of variable copper, nickel, and manganese contents on weld performance. This report presents an advanced evaluation of weld deposit performance based on new Charpy-V (Cv) and tension data and an analysis of temper embrittlement and radiation embrittlement processes. High fluence assessments confirm the high resistance to radiation embrittlement of the low copper content filler metal group. A 530 F (277 C) irradiation of one typical submerged arc weld deposit to a fluence of 3.8 × 1020 n/cm2 > 1 MeV did not elevate its Cv 30 ft-lb transition temperature to above 275 F (135 C) or reduce its Cv shelf energy level to below 50 ft-lb. Radiation embrittlement saturation was not evident. Temper embrittlement and radiation embrittlement development and the probable mechanisms of copper and phosphorus influences on radiation embrittlement sensitivity are analyzed with the aid of experimental data for the weld metals and A543 plate. Temper embrittlement and radiation embrittlement are shown to be additive effects which can occur simultaneously or sequentially. A separate component of irradiation effects, manifested as a strength increase without embrittlement, is revealed. The enhancement of radiation sensitivity by high copper content (≧0.16–0.27 percent Cu) is related to a copper influence on the radiation elevation of yield strength; the enhancement of radiation sensitivity of phosphorus is ascribed to a detrimental effect similar to that of temper embrittlement. It is proposed that copper acts to pin radiation-induced defect aggregates and dislocation arrays in the matrix and that phosphorus segregates during irradiation to weaken the interface of ferrite platelets and carbides.

Welding and brazing filler metals

A description of the welding and brazing filler metals most commonly used in nuclear-oriented applications is presented. The general classes of materials discussed are carbon steels, low-alloy steels, stainless steels, nickel and high-nickel alloys, aluminum, titanium and zirconium, refractory metals, and brazing filler metals. These filler metals are further categorized into the welding process or processes to which they are applicable, that is, shielded metal-arc, gas tungsten-arc, gas metal-arc, submerged-arc, and electroslag. The various factors involved in filler metal selection, such as mechanical properties, service temperature, and corrosion are considered. A discussion of the types of brazing fluxes and atmospheres is also presented.

Information from ultrasonic flaw detection systems

An ultrasonic flaw detection system can be considered as a series of filters, upon whose bandwidths depends the amount information that reaches the operator. This article emphasizes the value of matching the elements of the system. It also suggests that the B-scope display deserves more attention in industrial uses and gives examples of B-scope displays of a filler weld.

溶接構造用Al-Zn-Mg系合金の研究(第1報)

A study has been made of aging characteristics of Al-Zn-Mg alloy welds.The parent metal contained Al-4.1% Zn-1.6% Mg-0.3% Mn and the filler metals were 5056, 5356 alloys and parent metal fillers.All of the weldments could make almost the maximum recovery of strength in 90 days of nutural aging after welding. The weld strength, however, difinitely depended on welding processes, filler metals and previous heat treatments of parent metal. All of the undressed TIG and MIG-welds of 2 mm thick plate fractured at the heat-affected-zone when they were tensile-tested after natural aging of 90 days. The undressed TIG-welds of 5 mm thick plate fractured at the heat-affected-zone when they were tensiletested after natural aging of 90 days, but the dressed TIG-welds and all of the MIG-welds fractured at the weld metal.The strength of welds depends on the structure of heat-affected-zone and the aging characteristics of weld metal. The former is affected by the reversion of G-P zone and the growth of M' particles during welding, and the latter by the chemical composition of weld metal.

耐食性アルミニウム合金ANP板の消耗電極式アルゴンアーク熔接の研究(第2報)

Various tests on the inert-gas metal -arc welding of a corrosion resisting aluminum-manganese alloy "ANP", have been performed with ANP-O and ANP-1/4H plates, 1/4 in. in thickness, and various.consumable electrode wires, 52S, A54S, 56S and ANP. The present report Part 2 discusses the effects of welding conditions, surface treatments, filler wires, preheat and back-chipping on the occurence of porosities in bead weld or buutt weld, as well as the cracking tendencies of various filler wires in welding a slit-type cracking specimen.The essential factors to prevent porosities have been shown to be; chemical cleaning of filler wire, adequate arc length, higher heat input, less magnesium content, proper backing and precautions in the back pass, that is, back-chipping, slower welding speed or preheat. Electrode wires, ANP and A54S, were the least crack-sensitive.