Firewall training lab with layer 3 switch

Hello all,

I would like to set a firewall training lab in my lab environment.
Materials i have ;
2 Fortinet 60C utm device
1 HP 2910al switch
2 PC with 2 Network Card

The Internet gateway will be 172.16.20.1

switch config
============
hostname "utm_lab"
module 1 type J9145A
ip routing   >>>>>>>> i have to run this command for inter vlan comm ?
vlan 1
   name "DEFAULT_VLAN"
   untagged 6-24
   no untagged 1-5
   no ip address
   exit
vlan 10
   name "VLAN10"
   untagged 1
   ip address 10.0.10.254 255.255.255.0
   exit
vlan 20
   name "VLAN20"
   untagged 2
   ip address 10.0.20.254 255.255.255.0
   exit
vlan 30
   name "VLAN30"
   untagged 3
   ip address 10.0.30.254 255.255.255.0
   exit
vlan 40
   name "VLAN40"
   untagged 4
   ip address 10.0.40.254 255.255.255.0
   exit
vlan 50
   name "VLAN50"
   untagged 5
   ip address 172.16.20.254 255.255.255.0
   exit
ip route 0.0.0.0 0.0.0.0 172.16.20.1  >>> any dest. if  dont know the route


UTM 1
======
wan1 : 10.0.10.1/24
wan2 : 10.0.20.1/24
int     : 10.0.100.1 / 24

UTM 2
=====
wan1 : 10.0.30.1 /24
wan2 : 10.0.40.1 /24
int     : 10.0.200.1 /24

From 10.0.100.254 ( windows2008r2 ) PC i can reach to all vlan (10-50) but can't reach to 172.16.20.1 , what is wrong in this config ? any idea
How can i use my device to create a useful lab area in other way ?
Thanks