Cemented Carbide Drawing Die Composition for Corrosion and Toughness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Drawing dies for steel wire drawing face challenges with mechanical wear, corrosion, and fracture toughness, as existing cemented carbide materials often compromise on corrosion resistance when improving hardness and toughness.
Innovation Solution
A cemented carbide material composition comprising tungsten carbide with specific grain size, Co-Ni binder ratio, Cr, Mo, and absence of η-phase and V, providing high hardness, improved corrosion resistance, and fracture toughness, optimized for demanding wire drawing applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard strategies are used to improve corrosion resistance of carbide grades, then corrosion resistance is improved, but fracture toughness is lowered
Solution Approach 1:
The invention changes the chemical composition parameters of the binder phase by specifying precise ranges: Co content at 0.3-1.8 wt.-%, Ni at 0.1-0.5 wt.-%, Cr at 0.05-0.5 wt.-%, and Mo at 0.05-0.2 wt.-%. This multi-parameter optimization resolves the contradiction by achieving both improved corrosion resistance through Cr and Mo additions while maintaining fracture toughness through controlled Co and Ni levels.
Solution Approach 2:
The invention creates a composite binder phase system combining multiple metallic elements (Co, Ni, Cr, Mo) that work synergistically. The Co-Ni-Cr-Mo composite binder provides both corrosion resistance (from Cr and Mo) and adequate fracture toughness (from Co and Ni balance), resolving the contradiction between these two properties that cannot be achieved with single-element binders.
2Strength
If high hardness is pursued in drawing dies, then wear resistance is improved, but toughness and corrosion resistance deteriorate
Solution Approach 1:
The invention applies local quality by optimizing the binder phase composition specifically to balance hardness with toughness and corrosion resistance. The controlled Co content (0.3-1.8 wt.-%) provides adequate binder strength for hardness while Cr (0.05-0.5 wt.-%) and Mo (0.05-0.2 wt.-%) provide localized corrosion resistance at the grain boundaries, allowing the material to achieve high hardness without sacrificing reliability.
Solution Approach 2:
The multi-element binder phase (Co-Ni-Cr-Mo composite) creates a material system where different elements contribute different properties: Co and Ni for hardness and binder strength, Cr for corrosion resistance, and Mo for both corrosion resistance and grain boundary strengthening. This composite approach resolves the contradiction between hardness and reliability.
3Reliability
If binder composition is modified to improve corrosion resistance, then corrosion resistance is improved, but wettability of tungsten carbide grains deteriorates
Solution Approach 1:
The invention optimizes the parameter balance in the binder composition: Cr content is limited to 0.05-0.5 wt.-% and Mo to 0.05-0.2 wt.-% to maintain corrosion resistance without excessive amounts that would harm wettability. The Co content (0.3-1.8 wt.-%) and Ni content (0.1-0.5 wt.-%) are controlled to ensure adequate wettability of WC grains while allowing sufficient Cr and Mo for corrosion protection. This parameter balancing resolves the contradiction between corrosion resistance and wettability.
Data Source
AI summary
A drawing die made from cemented carbide material is formed of tungsten carbide and a metallic binder. The cemented carbide material includes: tungsten carbide with an average grain size of 0.15-1.3 μm, 0.5-5.0 wt.-% (Co+Ni), with a ratio Co/(Co+Ni) of 0.6-0.9; 0.1-1.0 wt.-% Cr, with 0.05≤Cr/(Co+Ni)≤0.22; 0.02-0.2 wt.-% Mo; and 0-0.04 wt.-% V. The cemented carbide material is substantially free from η-phase.