High-nickel wrought alloys alloy

Because of constitutional complexity, the exact chemistries of nickel-base superalloys must be controlled carehiUy in order to avoid the precipitation of deleterious topologically close-packed (TCP) phases and extraneous carbides after long-term high temperature exposure. Heat-treatment schedules and thermomechanical treatments in the case of wrought alloys also are important to provide optimum strength and performance. 

GoldJilloys, Wrought Type. Two types of wrought gold alloys were formerly recognized by the ADA specification no. 7 for the fabrication of orthodontic and prosthetic dental appHances, ie, type I, high-precious-metal alloys, and type II, low-precious-metal alloys (gold color). Alloys of this type are seldom used in the United States they have been replaced by stainless steels and nickel—titanium alloys. 

Pakhomova, N. A. and Levin, I. A., Effect of Grain Size on the Inter-crystalline Corrosion of Stainless Steel Type 18-8 , Zashch. Metal, 9, 676 (1973) C.A., 80, 86207j Brown, M. H. and Kirchner, R. W., Corrosion of High Alloy Weldments 1. Sensitisation of Wrought High Nickel Alloys , Corrosion, 29, 470 (1973)... 

The ecological and economic consequences of recovering 4500 lbs. per month of a 32% ferro-nickel alloy are impressive. This material can be saleable feedstock to industries producing wrought stainless steel, stainless steel castings, and high-nickel cast irons. Instead of a cost and liability, we now have a profit center. 

Wrought Nickel and High-Nickel Alloys. Some of the major nickel alloys, along with wrought nickel, are described in Table 1. 

Nickel is added to wrought alloys 2018, 2218 and 2618 for use in high-temperature exposures, 3XXX cast alloys for pistons, cylinder blocks and other engine parts subject to high temperatures. 

Alloys often selected for carburization resistance are the cast high-chromium, high-nickel HK and HP steels typically modified with silicon and the wrought alloys 8(X)/800H, type-330 stainless steel, 600, 601, HR-160 and HR-120. Type 310 stainless steel has good carburization resistance up to 1000 C, but is prone to <7 phase for-... 

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