Warm Forming of Medium-Manganese Steel for Lower Forming Forces

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for producing components from medium-manganese-containing flat steel products face challenges in achieving high degrees of deformation while minimizing forming forces.

Innovation Solution

A method involving preheating the flat steel product to a temperature between 60°C to Ac3, followed by forming into a component with initial forming steps at temperatures between 60°C to 450°C, which reduces work hardening and increases the degree of deformation, thereby lowering forming forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If forming is performed at room temperature or low temperature, then forming forces are high and degree of deformation is limited, but if temperature is increased to reduce forming forces, then material strength decreases

Engineering Contradiction:
Improveforming forcesVSAvoidmaterial strength
Core Design Contradiction:
ForceVSStrength

Solution Approach 1:

The steel strip is preheated to a temperature between 60°C and Ac3 before forming begins. This preliminary thermal treatment reduces the material's flow stress and work hardening rate, enabling high-degree deformation with reduced forming forces while maintaining adequate strength through controlled temperature management throughout the forming process

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the temperature parameter of the steel strip from room temperature to an elevated range (60°C to Ac3) before and during initial forming steps. This parameter change modifies the material's mechanical properties, specifically reducing work hardening and enabling greater ductility and formability without sacrificing ultimate material strength

Inventive Principle:
Principle #35Parameter changes

2Strength

If work hardening is increased to achieve high tensile strength, then tensile strength improves but degree of deformation and formability decrease

Engineering Contradiction:
Improvetensile strengthVSAvoidformability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The steel strip is preheated to a temperature between 60°C and Ac3 before forming begins. This preliminary thermal treatment reduces the material's flow stress and work hardening rate, enabling high-degree deformation with reduced forming forces while maintaining adequate strength through controlled temperature management throughout the forming process

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the temperature parameter of the steel strip from room temperature to an elevated range (60°C to Ac3) before and during initial forming steps. This parameter change modifies the material's mechanical properties, specifically reducing work hardening and enabling greater ductility and formability without sacrificing ultimate material strength

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If forming is performed without preheating, then process simplicity is maintained but degree of deformation is limited and forming forces are high

Engineering Contradiction:
Improveprocess simplicityVSAvoiddegree of deformation
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The steel strip is preheated to a temperature between 60°C and Ac3 before forming begins. This preliminary thermal treatment reduces the material's flow stress and work hardening rate, enabling high-degree deformation with reduced forming forces while maintaining adequate strength through controlled temperature management throughout the forming process

Inventive Principle:
Principle #10Preliminary action

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 enhances the maximum degree of forming, increases residual formability, and achieves tensile strengths of 800 MPa to 2000 MPa with elongations at break greater than 3% in severely formed areas.

Implementation Method 1

preheating the flat steel product to a desired temperature in the range from 60 °C to Ac3

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

a transformation of metastable austenite into martensite (TRIP effect) is completely or partially suppressed during the forming process, whereby deformation twins (TWIP effect) can form in the austenite

Methodology Applied
Scientific EffectPhase transformation: Phase Change

Implementation Method 3

reducing the work hardening during forming

Methodology Applied
Scientific EffectWork hardening: Shock Hardening

Data Source

PatentEP3512976B1Method for producing a shaped component from a medium-manganese flat steel product
Publication Date: 2025.06.18 SALZGITTER FLASHSTAHL GMBH

AI summary

The invention relates to a method for producing a component from a medium-manganese flat steel product with 4 to 12 wt% Mn, preferably more than 5 to less than 10 wt% Mn, and with TRIP/TWIP effect. In order to improve the degrees of deformation of the shaped component while at the same time reducing the forming forces, the invention proposes shaping the flat steel product into a component in a first shaping step at a temperature of the flat steel product of 60°C to below Ac3, preferably from 60°c to 450°C. The invention also relates to a component produced according to said method and to a use for said components.