
Fig. 1.
Hot stamping process

Fig. 2.
Passenger car beam

Fig. 3.
Stamping directions

Fig. 4.
Tools working surfaces

Fig. 5.
Stages of drawpieces forming

Fig. 7.
Distribution of cooling channels a) in the upper part of the tool b) in the lower part of the tool

Fig. 7.
Scaling factor of the pressure

Fig. 8.
Distribution of cooling channels a) in the upper part of the tool b) in the lower part of the tool

Fig. 9.
Temperature distribution in the drawpiece

Fig. 10.
Temperature distribution in tools

Fig. 11.
Share of martensite in the drawpiece

Fig. 12.
Parts of the tool a) lower part of the tool, b) upper part of the tool

Fig. 13.
Movable punch

Fig. 14.
Cooling water supply system for stamps

Fig. 15.
3D model of the coolant domain

Fig. 16.
FEM mesh of the punch model

Fig. 17.
Analysis boundary conditions

Fig. 18.
Temperature distribution in moving punches

Fig. 19.
The force of the drawpiece on the die

Fig. 20.
Drawpiece deformation after hardening (in relation to nominal shape)

Fig. 21.
FEM model for calculating the expansion of a) the lower part of the tools b) the upper part of the tools

Fig. 22.
Boundary conditions for the analysis of (a) the lower part of the tool (b) the upper part of the tool

Fig. 23.
Deformation in the lower part of the tool

Fig. 24.
Deformation in the upper part of the tool

Fig. 25.
Stamping die (lower part)

Fig. 26.
Photo of a sample of a drawpiece

Fig. 27.
Position of the measurement points on the drawpiece
Tab. 1.
Results of strength limit measurements Rm, MPa
| Measurement point number | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | ||
| Drawpiece number | W1 | 1747 | 1712 | 1700 | 1762 | 1795 | 1800 | 1732 | 1776 | 1745 | 1766 |
| W2 | 1712 | 1703 | 1757 | 1784 | 1779 | 1746 | 1708 | 1743 | 1723 | 1785 | |
| W3 | 1719 | 1731 | 1701 | 1745 | 1781 | 1708 | 1719 | 1761 | 1738 | 1777 | |
| W4 | 1770 | 1739 | 1779 | 1711 | 1767 | 1747 | 1779 | 1773 | 1710 | 1764 | |
| W5 | 1757 | 1771 | 1720 | 1709 | 1711 | 1701 | 1739 | 1780 | 1732 | 1799 | |
| W6 | 1792 | 1734 | 1758 | 1778 | 1746 | 1728 | 1703 | 1751 | 1700 | 1717 | |
| W7 | 1742 | 1751 | 1740 | 1786 | 1757 | 1702 | 1709 | 1744 | 1759 | 1729 | |
| W8 | 1789 | 1774 | 1799 | 1717 | 1771 | 1709 | 1700 | 1799 | 1743 | 1729 | |
| W9 | 1735 | 1724 | 1705 | 1713 | 1795 | 1758 | 1775 | 1730 | 1750 | 1745 | |
| W10 | 1764 | 1755 | 1773 | 1755 | 1764 | 1787 | 1720 | 1720 | 1759 | 1773 | |
| W11 | 1715 | 1770 | 1731 | 1720 | 1790 | 1758 | 1715 | 1771 | 1742 | 1755 | |
| W12 | 1728 | 1779 | 1745 | 1703 | 1784 | 1737 | 1704 | 1704 | 1729 | 1781 | |
| W13 | 1721 | 1753 | 1776 | 1740 | 1717 | 1714 | 1782 | 1740 | 1755 | 1726 | |
| W14 | 1742 | 1732 | 1718 | 1704 | 1761 | 1734 | 1730 | 1769 | 1797 | 1743 | |
| W15 | 1755 | 1747 | 1757 | 1800 | 1765 | 1724 | 1783 | 1792 | 1795 | 1742 | |
| W16 | 1777 | 1750 | 1733 | 1717 | 1756 | 1787 | 1771 | 1789 | 1774 | 1756 | |
| W17 | 1726 | 1790 | 1760 | 1769 | 1717 | 1741 | 1707 | 1785 | 1709 | 1771 | |
| W18 | 1741 | 1789 | 1789 | 1700 | 1708 | 1731 | 1767 | 1758 | 1742 | 1765 | |
| W19 | 1707 | 1797 | 1800 | 1800 | 1772 | 1735 | 1717 | 1793 | 1716 | 1731 | |
| W20 | 1775 | 1727 | 1711 | 1795 | 1700 | 1758 | 1738 | 1742 | 1787 | 1764 | |
Tab. 2.
Results of HV hardness measurements
| Measurement point number | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | ||
| Drawpiece number | W1 | 591 | 584 | 604 | 616 | 583 | 613 | 598 | 585 | 610 | 590 |
| W2 | 586 | 612 | 584 | 614 | 582 | 605 | 598 | 597 | 595 | 612 | |
| W3 | 619 | 594 | 615 | 614 | 613 | 612 | 594 | 605 | 613 | 582 | |
| W4 | 592 | 581 | 605 | 609 | 619 | 599 | 615 | 602 | 593 | 584 | |
| W5 | 599 | 599 | 620 | 599 | 616 | 590 | 587 | 601 | 598 | 580 | |
| W6 | 590 | 617 | 596 | 609 | 587 | 607 | 613 | 616 | 615 | 583 | |
| W7 | 607 | 613 | 612 | 609 | 593 | 603 | 599 | 589 | 593 | 607 | |
| W8 | 600 | 600 | 606 | 592 | 598 | 615 | 582 | 604 | 587 | 601 | |
| W9 | 598 | 590 | 606 | 593 | 597 | 595 | 618 | 607 | 598 | 580 | |
| W10 | 601 | 598 | 610 | 595 | 595 | 580 | 589 | 587 | 618 | 583 | |
| W11 | 583 | 606 | 582 | 593 | 610 | 602 | 605 | 615 | 588 | 601 | |
| W12 | 614 | 597 | 607 | 598 | 597 | 615 | 604 | 590 | 615 | 616 | |
| W13 | 617 | 582 | 618 | 583 | 585 | 593 | 596 | 582 | 587 | 601 | |
| W14 | 594 | 611 | 613 | 607 | 599 | 596 | 596 | 603 | 606 | 580 | |
| W15 | 592 | 581 | 595 | 615 | 585 | 605 | 618 | 618 | 591 | 607 | |
| W16 | 603 | 595 | 593 | 604 | 585 | 613 | 600 | 612 | 582 | 610 | |
| W17 | 610 | 618 | 580 | 611 | 594 | 611 | 595 | 608 | 615 | 600 | |
| W18 | 605 | 587 | 612 | 589 | 613 | 607 | 608 | 583 | 608 | 597 | |
| W19 | 594 | 602 | 599 | 603 | 603 | 609 | 612 | 588 | 619 | 609 | |
| W20 | 615 | 606 | 612 | 596 | 588 | 598 | 590 | 592 | 608 | 614 | |

Fig. 28.
Photo of a sample

Fig. 29.
The results of the tensile tests
Tab. 3.
Tensile test results
| Sample number | Yield strength Rp02, MPa | Tensile strength Rm, MPa |
|---|---|---|
| 1 | 1355 | 1851 |
| 2 | 1316 | 1873 |
| 3 | 1262 | 1830 |
| 4 | 1284 | 1838 |
| 5 | 1336 | 1804 |
| 6 | 1279 | 1858 |

Fig. 30.
Locations where samples were taken for testing

Fig. 31.
Locations where samples were taken for testing
Tab. 4.
Results of HV hardness measurements
| Measurement number | Imprint/value | |
|---|---|---|
| 1 | ![]() | 579.1 |
| 2 | ![]() | 538.7 |
| 3 | ![]() | 533.4 |
| 4 | ![]() | 561.9 |
| 5 | ![]() | 573.3 |
| 6 | ![]() | 583.6 |

Fig. 32.
Microstructure photograph of the sample

Fig. 33.
Example measurement report

Fig. 33.
The image from the thermal camera













