September_AMP_Digital

FEATURE A D V A N C E D M A T E R I A L S & P R O C E S S E S | S E P T E M B E R 2 0 2 0 4 4 Common laser heat treatable automotive materials include, but are not limited to: • D6510 Ductile Iron • D4512 Ductile Iron • S7 Tool Steel • S7140 Alloyed Steel • S0030 Non-Alloyed Steel • M2 Tool Steel • G2500 Grey Cast Iron • S0050A Alloyed Steel • 4140 Alloy Steel • G25HP Grey Cast Iron • A2 Tool Steel • 410 Stainless Steel • G3500 Grey Iron • D2 Tool Steel • 420 Stainless Steel 7 CASE STUDY To illustrate the potential for LHT, consider the follow- ing case study from a U.S. domestic OEM die supplier. This study concerns new part manufacture of automotive trim/ form dies. A mid-sized OEM typically produces 40 such dies in the year. For this process, both cost in hours while the product was being worked on, and also the calendar days for each step, were measured. The results are shown pictorially in a detailed table in Fig. 4 and are summarized here: • Laser heat treatment reduced the yearly cost for this product line from $436,000 to $312,000 at a billing rate of $50/hour, and from $697,000 to $499,200 at a billing rate of $80/hour, for a savings of 28.4%. • Delivery time dropped from 17 to 13 days, a net speedup of 23.5%. • Total energy reduction was significant, although not computed here. This may result in savings if carbon credits become monetized. Fig. 2 — Metallurgical cross-section of laser heat treated D6510 die material. Fig. 3 — Hardness profile of laser heat treated D6510 across the depth. Average hardness of 760 HV (62.5 HRC) was recorded on the D6510 test sample shown in Fig. 2. Fig. 4 — Detailed table comparing cost and time involved for conventional heat treating versus laser heat treating. 6