Study on Cavity Filling Defects and Tensile Properties of L-Shaped Profiled Rings

Area of Science:

• Materials Science
• Manufacturing Engineering
• Mechanical Engineering

Background:

• Forming L-shaped profiled rings is challenging due to asymmetrical geometry, leading to defects and poor mechanical properties.
• Existing methods struggle with integrated forming of complex profiles like L-shaped rings.

Purpose of the Study:

• To propose a novel rolling method for simultaneously producing two symmetric L-shaped rings from a C-shaped ring.
• To investigate and optimize rolling parameters to minimize defects and enhance the quality of L-shaped rings.

Main Methods:

• Development of a numerical model for C-shaped ring rolling to analyze cavity filling and geometric accuracy.
• Systematic investigation of the influence of rolling parameters (groove depth ratio, groove angle, rolling ratio) on forming defects.
• Application of the Box-Behnken optimization method for multi-objective optimization of rolling stability and ring quality.
• Experimental validation of the optimized rolling process.

Main Results:

• Forming defects increase with groove depth ratio and decrease with groove angle and rolling ratio.
• A constant ring growth velocity feeding strategy yields optimal geometric accuracy and strain uniformity.
• Optimized parameters, determined via Box-Behnken method, led to successful experimental preparation of C-shaped rings.
• The resulting C-shaped rings exhibit symmetric and uniform hardness distribution but retain anisotropy in tensile properties from the cast blank, with minimal improvement from heat treatment.

Conclusions:

• The novel C-shaped ring rolling method effectively addresses challenges in forming L-shaped rings.
• Optimized rolling parameters are crucial for achieving high-quality L-shaped rings with minimal defects.
• While geometric accuracy and hardness are improved, the inherent anisotropy of the cast material remains a factor affecting tensile properties.