1. The Introduction of Steel Grade
20Mn2 is alloy steel, with the implementation of standards GB/T3099-1999, the steel has good hardenability, tempering stability, bending performance and can be used in the production chain hoists lifting anchor chains and small size.
Xingtai Iron and Steel began to develop the steel from July 2007, now has the ability to produce the steel of φ6.5mm-φ14mm specifications.
2.Case Study
The following is a brief introduction of Xingtai Steel product φ8mm, φ10mm, φ12mm 20Mn2 and the use condition of a factory in Baoding
1.Production Process
Pickling - drawing - annealing - Subsection - pickling - Code Chain - Welding - correction - quenching and tempering - to try to pull - the status of surface treatment .
Annealing: annealing furnace (Bell furnace, annealing temperature 760 ℃ heat 7-8 hours, slow cooling 6 hours)
Drawing: the coiled φ8mm, φ10mm, φ12mm reducing 2mm by a drawing to φ6mm, φ8mm, φ10mm
2. Use Condition
Breaking the chain to do experiments, pull-off load fluctuations, in the 7.5-9 tons, the technician of the plant said it was probably due to the fluctuation of voltage and current frequency quenching, tempering temperature instability in the busy farming season. The sampling on the chain of Xingtai steel will ,test a total of four times, and the breaking load is respectively 9.8,9.8,10,9.3 tons, with small fluctuation and all meet the breaking load value ≥8.04 tons,The users expressed satisfaction with the performance index of Xingtai steel products.