Using Gas Metal Arc Welding (GMAW) with AHSS does present some technical hurdles. AHSS are sensitive to heat inputs of GMAW and can potentially suffer from microstructure changes and reductions in mechanical properties. It's a problem made all the worse in the down-gauged sheet made possible by AHSS strength. In his GDIS presentation, Ford's Elliott outlined some of the company's ongoing work to optimize GMAW process variables and weld-line geometry. For example, he identified a number of variables that can increase fatigue life of a lap-welding joint between a 3.4 mm AHSS (DP 600) and a 3.8 mm mild steel. Among the variables are decreasing wire feed speed and travel speed while increasing torch angle, push angle and the contact-to-work-distance.
The implementation of a new diesel fuel standard in the US has considerably improved the environmental performance of diesel vehicles. The Environmental Protection Agency (EPA) says that the new ultra-low sulfur diesel (ULSD) fuel has combined with other improved technologies to reduce diesel's particulate matter (PM) emissions by 99%.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.