Author: Daniel J. Schaeffler, Ph.D. First published in the December 2019 issue of MetalForming Magazine We exercise customer choice daily, from the car we drive to the cell phone we use. Pretty much every vehicle can get you from Point A to Point B, and every phone can at least initiate a call. Price, features and quality primarily influence our decision to choose one product over another. Similar considerations are [...]
Author: Daniel J. Schaeffler, Ph.D. First published in the December 2018 issue of MetalForming Magazine Simulation has made inroads into the metalforming community as an ideal way to predict what will occur when sheetmetal of known properties is subjected to known deformation forces. It saves days of trial-and-error, helping to evaluate what-if scenarios associated with variables such as metal grade and thickness, binder and addendum designs, and blank shape. It [...]
Author: Daniel J. Schaeffler, Ph.D. First published in the November 2018 issue of MetalForming Magazine Bethlehem Steel, U.S. Steel, Alcoa, American Can, General Electric, General Motors, Goodyear and Navistar. These eight manufacturing companies were among the 30 listed companies on the Dow Jones Industrial Average in 1988, MetalForming magazine’s first year. None of these currently occupy the Dow, and two no longer exist. A lot can change in 30 years, [...]
Author: Daniel J. Schaeffler, Ph.D. First published in the August 2018 issue of MetalForming Magazine Every stamped part contains at least some sources of variation that will never be eliminated—perhaps from the sheetmetal, lubrication, stamping process or any one of the many other aspects of the forming system. It is important to understand the sources of variation so that we can design our forming system to be more tolerant [...]
Author: Daniel J. Schaeffler, Ph.D. First published in the July 2018 issue of MetalForming Magazine With a part to manufacture, your first decisions revolve around how to generate that part and what material to use. Manufacturing options include casting, hydroforming and 3D printing, but you already have the experience and infrastructure for stamping. Factors such as cost, weight, corrosion resistance, strength and stiffness go into the discussion of what sheetmetal [...]
Thinning and Circle Grid (Surface) Strain Analyses are Engineering Quality tools that can help determine where trouble spots could develop during the production processing of your parts. The forming limit of a given steel is based on the thickness and the strain hardening exponent (n-value). The forming limit for other alloys must be determined experimentally. Knowing these parameters, and their minimum values likely to be encountered in production, it is [...]
Advanced High Strength Steels have been gaining ground in an automotive industry hunting for all the weight savings it can while satisfying or surpassing safety standards. The material could be called the next step in steel's evolution toward exhibiting the high-strength, lightweight characteristics of more expensive materials, like aluminum and magnesium. Challenges arise, however, from a formability standpoint. The varieties of AHSS do exhibit high formability, but in entirely different [...]
Author: Daniel J. Schaeffler, Ph.D. First published in the June 2018 issue of MetalForming Magazine Stainless steels can corrode—they’re called stain-less after all, not stain-free. They offer many grades from which to choose, providing a wide spectrum of uses and challenges. The five main categories of stainless steels, designated by their predominant microstructural phases and characteristics: Austenitic Ferritic Martensitic Duplex Precipitation-hardened Like all steels, each of these have iron as [...]
20% Maximum Thinning rule should not be a rule Circle Grid Analysis and Thickness Strain Analysis Forming AHSS: Playing By New Rules Introduction to Advanced High Strength Steels – Grades Introduction to Advanced High Strength Steels – Processing Secondary Work Embrittlement [...]
Everyone likes to have a “Rule of Thumb” to use as a quick and easy guide. To make the best use of these maxims, it helps to understand where they came from, and what the limitations are in their use. When it comes to taking the right steps to ensure a robust stamping process, a surface strain analysis using a forming limit diagram is recommended. The forming limit curve should [...]
