Test Background
Acid leaching test is a test method to reveal the low-magnification structure of steel materials. In the low-magnification inspection of steel, acid leaching is one of the commonly used methods because the acid leaching test equipment is simple and easy to operate. It can clearly display various defective structures in the steel, such as cracks, inclusions, looseness, segregation and pores, especially forgings.
The acid leaching test of steel wire and steel wire products can measure its acid leaching performance and detect surface defects of steel wires. Zhongke Testing Reliability Experiment Center has the capability of reliability testing of various steel wires and steel wire products, and provides professional acid leaching testing services for steel wires and steel wire products.
Scope of tests
is suitable for cold-worked steel wires, annealed steel wires, quenched and tempered steel wires and coated steel wires with constant cross-section (circular or special-shaped).
Test method
1. The sample should be properly degreased. Samples that have been deformed by drawing should be rinsed and dried. For high carbon steel samples, the stress was relieved at 400 ℃ ~ 500 ℃ for 15 minutes, and then cooled to room temperature for etching.
2. The sample is immersed in a hydrochloric acid aqueous solution with a volume concentration of 50% and a minimum temperature of 60°C. Except for samples with a diameter greater than 5.0 mm and annealed structures, the maximum etching time shall not exceed 5 min. Depending on the size of the sample diameter, the etching time will be shortened by 2 seconds for every 0.025 mm decrease in diameter.
3. For steel wires with a diameter greater than 5.0 mm and annealed steel wires, the etching time is 10 minutes.
4. The sample is inspected for surface defects. In order to determine the depth of the defect, the size difference before and after etching should be recorded. To ensure the accuracy of defect measurement, analysis can be performed with the help of a stereomicroscope.
Test standard:
GB T 36915-2019 Steel wire and steel wire products General test method
ISO 22034-1: 2007 Steel wire and steel wire products Part 1: General test method
KS D ISO 22034-1-2009 Steel wire and steel wire products Part 1: General test methods
GOST R ISO 22034-1-2013 Steel wire and steel wire products Part 1 General test methods
GB/T 2975 Steel and steel products Sampling locations and sample preparation for mechanical property testing
