Nickel based alloy
High temperature alloys refer to a type of metal material based on iron, nickel, and cobalt that can work for a long time at high temperatures above 600 ℃ and under certain stress conditions. They have high high-temperature strength, good oxidation and corrosion resistance, good fatigue performance, and fracture toughness, among other comprehensive properties. They are referred to as superalloys in Europe and America. Usually used for components that work for a long time under high temperatures (600-1200 ℃) and complex stress conditions.
Nickel based alloys are currently the most widely used high-temperature alloys, mainly used in working environments such as high temperature, strong acid or alkali, and strong oxidation. Its development and use began in the late 1930s, with the emergence of jet aircraft requiring higher performance of high-temperature alloys. This article will introduce nickel based alloys from the following aspects.
1、 Category
Classified by performance:
Nickel based corrosion-resistant alloy: The main alloying elements are copper, chromium, and molybdenum. It has good comprehensive performance and can withstand various acid corrosion and stress corrosion. There are mainly nickel copper (Ni Cu) alloys (Monel alloy), nickel chromium (Ni Cr) alloys (nickel based heat resistant alloys, Incoloy, Inconel series), nickel molybdenum (Ni Mo) alloys (Hastelloy B series), nickel chromium molybdenum (Ni Cr Mo) alloys (mainly referring to Hastelloy C series), etc. At the same time, pure nickel is also a typical representative of nickel based corrosion-resistant alloys.
Nickel based wear-resistant alloy: The main alloying elements are chromium, molybdenum, tungsten, and also contain small amounts of niobium, tantalum, and indium. In addition to wear resistance, it also has excellent oxidation resistance, corrosion resistance, and welding performance.
Nickel based precision alloys: including nickel based soft magnetic alloys, nickel based precision resistance alloys, and nickel based electric heating alloys. The most commonly used soft magnetic alloy is a permalloy containing about 80% nickel, which has high maximum and initial magnetic permeability, low coercivity, and is an important iron core material in the electronic industry. The main alloying elements of nickel based precision resistance alloys are chromium, aluminum, and copper. This alloy has high resistivity, low resistivity temperature coefficient, and good corrosion resistance, and is used for making resistors. Nickel based electric heating alloy is a nickel alloy containing 20% chromium, which has good oxidation and corrosion resistance, and can be used for a long time at temperatures ranging from 1000 to 1100 ℃.
Nickel based memory alloy: A nickel alloy containing 50 (at)% titanium has a recovery temperature of 70 ℃ and good shape memory effect. A small change in the proportion of nickel and titanium components can result in a change in the recovery temperature within the range of 30-100 ℃.
