Rolling Sliding Member Composition for Shorter Carburizing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing rolling sliding members using carburized steels like SCM and SNCM require long carburizing treatments, leading to increased production costs and potential reduction in surface layer strength due to grain boundary oxide layer formation, which can result in cracks and foreign substances entering the product, affecting lifespan.
Innovation Solution
A rolling sliding member with a base composition of 0.30-0.45% carbon, 0.15-0.45% silicon, 0.40-2.00% chromium, 0.10-0.35% molybdenum, 0.20-0.40% vanadium, and 0.005-0.100% aluminum, with a surface layer having Vickers hardness of 700-800 and 25-50% retained austenite, where the grain boundary oxide layer thickness is controlled to ≤1.4×10^-3 times the equivalent diameter, allowing for a shorter treatment time and reduced production costs while maintaining strength and crack resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a carburizing treatment is performed for a long time to obtain a surface layer that can improve product lifespan, then the surface layer hardness is improved, but the production costs increase
Solution Approach 1:
The patent changes the chemical composition parameters of the base material by specifying precise ranges for carbon (0.30-0.45%), silicon (0.15-0.45%), manganese (0.40-1.50%), chromium (0.60-2.00%), molybdenum (0.10-0.35%), vanadium (0.20-0.40%), and aluminum (0.005-0.100%). This compositional parameter change enables the material to achieve the required surface layer hardness with a shorter carburizing treatment time, thereby reducing production costs while maintaining product lifespan.
2Strength
If a carburizing treatment is performed for a long time to obtain a surface layer that can improve product lifespan, then the surface layer hardness is improved, but the production costs increase
Solution Approach 1:
The patent optimizes the chemical composition parameters of the base material with specific ranges for multiple alloying elements. This parameter optimization enables faster carburizing treatment, improving production efficiency while achieving the required surface layer hardness for product lifespan improvement.
3Stability of the object's composition
If a carburizing treatment is performed for a long time, crystal grains are coarsened, so secondary quenching is performed to adjust crystal grain size, but production costs further increase
Solution Approach 1:
The patent specifies precise compositional parameters including carbon (0.30-0.45%), silicon (0.15-0.45%), manganese (0.40-1.50%), chromium (0.60-2.00%), molybdenum (0.10-0.35%), vanadium (0.20-0.40%), and aluminum (0.005-0.100%). These parameter changes enable the material to maintain fine crystal grain structure even with shorter carburizing treatment times, eliminating the need for secondary quenching and reducing total treatment time.
4Strength
If a carburizing treatment is performed for a long time, formation of a grain boundary oxide layer is facilitated, but the strength of the surface layer is reduced
Solution Approach 1:
The patent changes the chemical composition parameters by specifying precise ranges for multiple alloying elements, particularly aluminum (0.005-0.100%) and other deoxidizing elements. These parameter changes suppress grain boundary oxide layer formation during shorter carburizing treatment, maintaining surface layer strength while reducing treatment time.
5Strength
If the grain boundary oxide layer remains on the rolling sliding member, cracks are likely to occur when a load is applied, but the crack resistance is reduced
Solution Approach 1:
The patent optimizes the chemical composition with specific ranges for aluminum (0.005-0.100%) and other elements to suppress grain boundary oxide layer formation. This parameter optimization improves crack resistance by preventing oxide layer formation that would serve as crack initiation sites under load.
6Reliability
If the grain boundary oxide layer falls off, foreign substances may be caught in the inside of the product, but the product lifespan is adversely affected
Solution Approach 1:
The patent changes the chemical composition parameters, particularly aluminum content (0.005-0.100%) and other deoxidizing elements, to suppress grain boundary oxide layer formation. This prevents oxide layer detachment and subsequent foreign substance contamination, improving product reliability and lifespan.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces production costs, enhances the rolling fatigue lifespan, and prevents foreign substances from entering the product, thereby improving the overall product lifespan by ensuring a hard, tough surface layer and controlled grain boundary oxide layer formation.
Implementation Method 1
a carburizing treatment and the like are performed on a molding raw material containing a carburized steel
Implementation Method 2
The surface layer has a Vickers hardness of 700 to 800
Implementation Method 3
it is necessary to perform secondary quenching in order to adjust the size of crystal grains
Implementation Method 4
The base part has a composition including 0.30 mass % to 0.45 mass % of carbon, 0.15 mass % to 0.45 mass % of silicon, 0.40 mass % to 1.50 mass % of manganese, 0.60 mass % to 2.00 mass % of chromium, 0.10 mass % to 0.35 mass % of molybdenum, 0.20 mass % to 0.40 mass % of vanadium
Data Source
AI summary
A rolling sliding member includes a base part and a surface layer. The base part has a composition that includes 0.30 mass % to 0.45 mass % of carbon, 0.15 mass % to 0.45 mass % of silicon, 0.40 to 1.50 mass % of manganese, 0.60 mass % to 2.00 mass % of chromium, 0.10 mass % to 0.35 mass % of molybdenum, 0.20 mass % to 0.40 mass % of vanadium, and 0.005 mass % to 0.100 mass % of aluminum, and a remainder of iron and inevitable impurities. The surface layer is positioned around the base part. The surface layer has a Vickers hardness of 700 to 800 and a retained austenite content of 25 volume % to 50 volume %. The thickness of a grain boundary oxide layer satisfies Formula: thickness of grain boundary oxide layer≤equivalent diameter of rolling sliding member×1.4×10−3.