Stress corrosion testing of metals and alloys

It is generally believed that cracks are the result of stress corrosion, but under the action of stress, other forms may also appear, such as intergranular corrosion or crack propagation. In addition to embrittlement and exfoliation corrosion caused by liquid metal, all phenomena caused by the simultaneous action of a corrosive environment and tensile stress, including the dissolution of metal or the action of hydrogen entering the metal, belong to the category of stress corrosion.
Stress corrosion refers to the combined action process of metal corrosion and strain caused by applied or residual stress. Metal and alloy stress corrosion testing determines metal stress corrosion susceptibility.
Zhongke Testing Reliability Experiment Center has the ability to test the corrosion resistance of various metals and alloys, and provides professional stress corrosion testing services for metals and alloys.

Metals: Common metals include gold, silver, copper, iron, manganese, zinc, etc., which can be divided into ferrous metals, non-ferrous metals, light metals, rare metals, heavy metals, precious metals, etc.
Alloy: It is classified as a certain alloy according to the name of the main metal with a large content in the alloy. It is generally divided into mixed alloys, solid solution alloys, intermetallic compound alloys, etc. Specific examples include solder, bismuth-cadmium alloy, brass composed of copper and zinc (β-brass, γ-brass and ε-brass), etc.

1. Constant strain test Since various forms of bending tests fall into this category, constant strain test is by far the most popular type of test. In addition, such tests often simulate the stresses associated with service failure.
2. Constant load test This type of test can better simulate corrosion damage caused by external or working stress. In addition, because the driving force increases with crack growth, the test may fail earlier or fail completely than the constant strain test.
3. Slow strain rate test Because dynamic plastic strain is a key factor in the crack initiation and expansion process, the application of slow dynamic strain is important for constant total strain or constant load tests.

GB/T 15970.1-2018 Corrosion of metals and alloys Stress corrosion testing Part 1: General test methods
GB/T 15970.7-2017 Corrosion of metals and alloys Stress corrosion test Part 7: Slow strain rate test
GB/T 15970.2-2018 Corrosion of metals and alloys Stress corrosion testing Part 1: Preparation and application of curved beam specimens
GB/T 15970.3-2018 Corrosion of metals and alloys Stress corrosion testing Part 1: Preparation and application of U-shaped bend specimens
GB/T 15970.4-2018 Corrosion of metals and alloys Stress corrosion testing Part 1: Preparation and application of uniaxial loading tensile specimens
GB/T 15970.5-2018 Corrosion of metals and alloys Stress corrosion testing Part 1: Preparation and application of C-ring specimens
GB/T 15970.6-2018 Corrosion of metals and alloys Stress corrosion testing Part 1: Preparation and application of pre-cracked specimens under constant load and constant displacement
GB/T 15970.8-2018 Corrosion of metals and alloys Stress corrosion testing Part 1: Preparation and application of welding specimens
GB/T 15970.9-2018 Corrosion of metals and alloys Stress corrosion testing Part 1: Preparation and application of pre-cracked specimens under incremental load or incremental displacement
GB/T 15970.10-2018 Corrosion of metals and alloys Stress corrosion test Part 1: Reverse U-bend test method
GB/T 15970.11-2018 Corrosion of metals and alloys Stress corrosion testing Part 1: Guidelines for hydrogen embrittlement and hydrogen-induced cracking testing of metals and alloys
0 ISO 7539-1: 2012 Corrosion of metals and alloys Stress corrosion testing Part 1: General test methods